Chapter 2-Analysing Linear Motion

Chapter 2 Force And Motion

2.1 Analysing Linear Motion

ITeach – Physics Form 4

Chapter 2 Force And Motion

Analysing Linear Motion Linear Motion

Linear motion is the motion of an object whose path is a straight line

Running a 100 m race

A moving bullet

An apple falling from tree ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Gerakan Linear

Gerakan linear ialah gerakan ssesuatu objek dalam lintasan lurus atau dalam garis lurus.

Berlari sejauh 100 m

Peluru yang sedang bergerak

Epal jatuh daripada pokok ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Speed And Velocit y

Speed

Velocity

A scalar quantity

A vector quantity

Rate of change of distance

Rate of change of displacement

Speed = distance travelled / time

Velocity = displacement / time

An athlete ran a 400 m race in a time of 80.0 seconds.

Example

Distance ran = 400 m Speed = distance / time = 400 / 80.0 = 5 m s-1 ITeach – Physics Form 4

Displacement = zero (0) m Velocity = displacement / time = 0 / 80.0 = 0 m s-1

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Laju dan Halaju

Laju

Halaju

Suatu kuantiti skalar

Suatu kuantiti vektor

Kadar perubahan jarak

Kadar perubahan sesaran

Laju = jarak dilalui / masa

Halaju = sesaran / masa

Contoh Seorang atlet berlari dalam lumba lari 400 m dalam masa 80.0 saat.

Jarak berlari = 400 m Laju

ITeach – Fizizk Tingkatan 4

= jarak / masa = 400 / 80.0 = 5 m s-1

Sesaran = Sifar (0) m Halaju

= sesaran / masa = 0 / 80.0 = 0 m s-1

Chapter 2 Force And Motion

Analysing Linear Motion Acceleration And Deceleration

When an object accelerates, its velocity changes.

A vector quantity

For an object in linear motion

Acceleration, a =

Object accelerating, velocity Object decelerating, velocity

final velocity, v – initial velocity, u time, t

u

is the velocity of an object at the start of its motion

v

is the velocity of an object at the end of its motion

a

is the rate of change of velocity

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Pecutan dan Nyahpecutan

Apabila suatu objek memecut, halajunya berubah.

Suatu kuantiti vektor

Objek bergerak dalam garisan linear

Pecutan , a =

Objek memecut , halaju Objek nyahpecut, halaju

Halaju akhir, v – Halaju awal, u Masa, t

u

Halaju objek ketika ia mula bergerak

v

Halaju objek di akhir gerakan

a

Kadar perubahan halaju

ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Numerical Example Acceleration And Deceleration A car starts form rest and accelerates uniformly achieving a velocity of 50 m s-1 in a time of 10 seconds.

Initial velocity

u = 0 m s-1 (car at rest / stationary)

Final velocity Time

v = 50 m s-1 t = 10 s Acceleration, a = v – u t 50 – 0 a= 10 a = 5 m s-2

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Contoh Berangka Pecutan dan Nyahpecutan Sebuah kereta bergerak daripada keadaan rehat dengan pecutan seragam sehingga ia mencapai halaju 50 m s-1 dalam masa 10 saat.

Halaju awal

u = 0 m s-1 (kereta dalam keadaan rehat / pegun)

Halaju akhir Masa

v = 50 m s-1 t = 10 s Pecutan

ITeach – Fizik Tingkatan 4

,a= v–u t 50 – 0 a= 10 a = 5 m s-2

Chapter 2 Force And Motion

Analysing Linear Motion Ticker Timer ticker tape

Used together with a trolley to study linear motion in the laboratory.

Powered by a 12 V AC power supply of frequency 50 Hertz.

magnet AC power coil

The metal strip (vibrator) vibrates 50 times in 1 second when connected to power.

The vibrating metal strip punches dots on the carbonized ticker tape.

timer

ITeach – Physics Form 4

vibrating bar

trolley

runway

carbon paper disc

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Jangka Masa Detik Digunakan bersama troli untuk gerakan linear di dalam makmal.

mengkaji

magnet

Satu bekalan kuasa 12 V AC digunakan dengan frekuensi 50 Hertz.

Kuasa AC

Jalur bergetar bergetar 50 kali setiap 1 saat apabila ia bersambung dengan bekalan kuasa.

gelung

Jalur bergetar menebuk titik pada pita detik berkarbon.

Jangka masa

ITeach – Fizik Tingkatan 4

Pita jangka masa detik

Jalur bergetar

troli

landasan

Pita detik berkarbon

Chapter 2 Force And Motion

Analysing Linear Motion The Ticker Tape •

Shows a comprehensive record of the motion of the trolley that pulls the ticker tape through the ticker timer. dots

1 tick •

The vibration metal strip makes 51 dots on the ticker tape per second.

•

The time interval between two successive dots is called a tick.

•

50 ticks are made on the ticker tape in 1 second.

•

Therefore the duration of 1 tick is 1/50 = 0.02 seconds.

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Pita Jangka Masa Detik

•

Menunjukkan rekod gerakan troli. titik

1 detik •

Jalur berdetik membuat 51 titik pada pita jangka masa detik setiap 1 saat.

•

Sela masa antara dua titik dipanggil satu detik.

•

Terdapat 50 titik pada pita jangka masa detik dalam masa 1 saat.

•

Tempoh masa untuk setiap 1 titik ialah 1/50 = 0.02 saat.

ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Analysis Of The Ticker Tape Type Of Motion The motion of an object can be deduced by studying the ticks formed on the ticker tape.

Ticker tape

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Gap between successive dots

Type of motion

Uniform but small

low but velocity.

uniform

Uniform but big

high but velocity.

uniform

Increasing in size

velocity increases, object accelerating.

Decreasing in size

velocity decreases, object decelerating.

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Menganalisis Pita Jangka Masa Detik Jenis Gerakan Jenis gerakan objek boleh ditakikkan dari jarak antara titik pada pita jangka masa detik.

Pita jangka masa detik

ITeach – Fizik Tingkatan 4

Sela antara titik

Jenis gerakan

Seragam dan jarak antara titik kecil

Halaju perlahan dan seragam

Seragam dan jarak antara titik besar

Halaju tinggi dan seragam

Jarak antara titik bertambah

Halaju bertambah, objek memecut

Jarak antara titik berkurangan

Halaju berkurangan, objek nyahpecut

Chapter 2 Force And Motion

Analysing Linear Motion Analysis Of The Ticker Tape Determining Average Velocity

The speed of the object pulling the ticker tape through the ticker timer can be determined as such Average velocity =

length of n ticks time for n ticks

Example 8 cm Number of ticks = 3 length of 3 ticks = 8 cm time for 3 ticks = (3)(0.02) = 0.06 s Average velocity = (length of 3 ticks)/(time for 3 ticks) = 8 cm / 0.06 s = 133.33 cm s-1 ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Menganalisis Pita Jangka Masa Detik Menentukan Purata Halaju

Purata halaju objek dapat ditentukan melalui:

Purata halaju =

Panjang n titik Masa bagi n titik

Contoh 8 cm Bilangan titik = 3 Panjang 3 titik = 8 cm Masa bagi 3 titik = (3)(0.02) = 0.06 s Purata halaju

ITeach – Fizik Tingkatan 4

= (penjang 3 titik)/(masa bagi 3 titik) = 8 cm / 0.06 s = 133.33 cm s-1

Chapter 2 Force And Motion

Analysing Linear Motion Analysis Of The Ticker Tape

0.4 cm Initial velocity, u = 0.4cm / 0.02s = 20 cm/s Final velocity , v = 2.4cm / 0.02s = 120 cm/s Time = ( total number of ticks –1 ) x ( 0.02 ) = ( 11 – 1 ) x ( 0.02 ) = 10 × 0.02 = 0.2s

ITeach – Physics Form 4

10 ticks 11 ticks

9 ticks

8 ticks

7 ticks

6 ticks

5 ticks

4 ticks

1 tick 2 ticks 3 ticks

Determining Acceleration

2.4 cm Acceleration, a = v – u t 120 – 20 a= 0.2 a = 100 / 0.2 = 500 cm s-2

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Menganalisis Pita Jangka Masa Detik

0.4 cm Halaju awal , u = 0.4cm / 0.02s = 20 cm/s Halaju akhir , v = 2.4cm / 0.02s = 120 cm/s Masa = ( Jumlah bilangan titik –1 ) x ( 0.02 ) = ( 11 – 1 ) x ( 0.02 ) = 10 × 0.02 = 0.2s

ITeach – Fizik Tingkatan 4

10 titik 11 titik

9 titik

8 titik

7 titik

6 titik

5 titik

4 titik

1 titik 2 titik 3 titik

Menentukan Pecutan

2.4 cm Pecutan

,a= v–u t 120 – 20 a= 0.2 a = 100 / 0.2 = 500 cm s-2

Chapter 2 Force And Motion

Analysing Linear Motion Characteristics Of Ticker Tape Chart - Uniform Velocity

The distance between successive dots are equally spaced.

All the ticker tapes are of the same length.

Length (cm) 7 6 5 4 3 2 1 0

Time ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Ciri-ciri Carta Pita Jangka Masa Detik – Halaju Sekata

Jarak antara titik-titik adalah sama.

Keratan pita sama panjang Panjang (cm) 7 6 5 4 3 2 1 0

Masa ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Characteristics Of Ticker Tape Chart - Uniform Acceleration

Distance between successive dots increases uniformly.

Length of ticker tapes increases uniformly.

Length / cm 7.0 6.0 5.0 4.0 3.0 2.0 Time ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Ciri-ciri Carta Pita Jangka Masa Detik – Pecutan Seragam

Jarak antara titik bertambah secara seragam Panjang keratan pita bertambah secara seragam Panjang / cm 7.0 6.0 5.0 4.0 3.0 2.0 Masa ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Characteristics Of Ticker Tape Chart - Uniform Deceleration

Distance between successive dots decreases uniformly.

Length of ticker tapes decreases uniformly.

Length / cm 7.0 6.0 5.0 4.0 3.0 2.0 Time ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Ciri-ciri Carta Pita Jangka Masa Detik – Nyahpecutan Seragam

Jarak antara titik berkurangan secara seragam Panjang pita berkurangan secara seragam Panjang / cm 7.0 6.0 5.0 4.0 3.0 2.0 Masa ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Equations Of Linear Motion With Constant Acceleration

The three equations of linear motion with constant acceleration

v = u + at

s = ut +

where

ITeach – Physics Form 4

1 2 at 2

u

=

initial velocity

v

=

final velocity

a

=

acceleration

t

=

time

s

=

displacement

v 2 = u 2 + 2as

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Persamaan Gerakan Linear dengan Pecutan Seragam

Tiga persamaan gerakan linear dengan pecutan seragam

v = u + at

s = ut +

dimana

ITeach – Fizik Tingkatan 4

1 2 at 2

u

=

Halaju awal

v

=

Halaju akhir

a

=

Pecutan

t

=

Masa

s

=

Sesaran

v 2 = u 2 + 2as

Chapter 2 Force And Motion

Analysing Linear Motion Equations Of Linear Motion With Constant Acceleration Example 1

A car starts from rest, accelerates with a uniform acceleration of 3 ms-2. What will the velocity of the car after it had travelled for 10 seconds ?

Solution : initial velocity u = 0 ms-1 (since the car is at rest /stationary ) acceleration a = 3 ms-2 time taken t = 10 s final velocity v=?

Using the equation,

v = u + at = 0 + (3)(10)

= 30 m s-1 oving at a velocity of 30 ms-1 after 10 seconds.

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Persamaan Gerakan Linear dengan Pecutan Seragam Contoh 1

Sebuah kereta bergerak daripada keadaan rehat memecut dengan pecutan seragam 3 ms-2. Berapakah pecutan kereta itu selepas bergerak selama 10 saat?

Penyelesaian : Halaju awal u = 0 ms-1 (kereta dalam keadaan rehat sebelum bergerak) Pecutan a = 3 ms-2 Masa t = 10 s Halaju akhir v=?

Menggunakan persamaan,

v = u + at = 0 + (3)(10)

= 30 m s-1 gerak pada halaju 30 ms-1 selepas 10 saat.

ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

Analysing Linear Motion Equations Of Linear Motion With Constant Acceleration Example 2 A rocket being launched accelerates vertically upwards with a uniform acceleration of 50 ms-2.

How far is the rocket from the surface of the earth after 2 minutes of the launch?

Solution : initial velocity

u = 0 ms-1 (rocket was stationary before launched)

celeration

a = 50 ms-2 t = 2 × 60 = 120 s height from earth’s surface s=?

Using the equation,

ITeach – Physics Form 4

1 s = ut + at 2 2

1 (50)(120)2 2 = 360000 m = 360 km = (0)(120) +

Bab 2 Daya dan Gerakan

Menganalisis Gerakan Linear Persamaan Gerakan Linear dengan Pecutan Seragam Contoh 2 Sebuah roket yang baru dilancarkan memecut secara menegak ke atas dengan pecutan seragam 50 ms-2.

Berapa jauhkah roket itu daripada permukaan Bumi selepas 2 minit dilancarkan?

Penyelesaian : Halaju awal

cutan

u = 0 ms-1 (roket dalam keadaan rehat sebelum dilancarkan)

a = 50 ms-2 t = 2 Ă— 60 = 120 s ggian daripada permukaan Bumi s = ?

Menggunakan persamaan,

ITeach – Fizik Tingkatan 4

1 s = ut + at 2 2

1 (50)(120)2 2 = 360000 m = 360 km = (0)(120) +

Chapter 2 Force And Motion

2.2 Analysing Motion Graphs

ITeach – Physics Form 4

Chapter 2 Forces and Motion

Analysing Motion Fraphs Displacement – time graphs

To show the displacement of an object changes with time.

Can determine the displacement of an object at any time.

Can determine the time taken for an object to cover certain displacement.

Example

Displacement / m

At time t = 40 s, the displacement of object is 60 m.

75 60 45 30 15

Time/s 10 ITeach – Physics Form 4

20

30

40

50

The time taken for the object at the displacement 15 m is 10 s.

Bab 2 Daya dan Gerakan

Menganalisis Graf Gerakan Graf sesaran - masa

Menunjukkan sesaran objek berubah dengan masa.

Boleh menentukan sesaran objek pada masa tertentu.

Boleh menentukan masa yang diambil oleh suatu objek untuk setiap sesaran.

Contoh

Sesaran / m

Pada masa t = 40 s, sesaran objek ialah 60 m.

75 60 45 30 15

Masa/s 10 ITeach – Fizik Tingkatan 4

20

30

40

50

Masa yang diambil objek pada sesaran 15 m ialah 10 s.

Chapter 2 Force And Motion

Analysing Motion Graphs Determining Velocity Displacement-Time Graph

velocity = gradient of displacement-time graph

Example

Displacement/m

velocity = gradient of displacementtime graph 75

velocity =

60 45

=

30 15

Time/s 10

ITeach – Physics Form 4

20

30

40

50

60 – 15 40 – 10 45 30

= 1.5 ms-1

Bab 2 Daya dan Gerakan

Menganalisis Graf Gerakan Menentukan Halaju – Graf Sesaran - Mas

Halaju = Kecerunan graf sesaran - masa

Contoh

Sesaran/m

Halaju = kecerunan graf sesaran masa 75

Halaju

60

=

45

=

30 15

Masa/s 10

ITeach – Fizik Tingkatan 4

20

30

40

50

60 – 15 40 – 10 45 30

= 1.5 ms-1

Chapter 2 Force And Motion

Analysing Motion Graphs Velocity-Time Graph

shows how the velocity of a moving object changes with time.

Example Velocity, v/ms-1 30

When time, t = 4 s, the velocity of the object is 20 ms-1

25 20 15 10

It takes 3 seconds for the object to achieve a velocity of 15 ms-1

5

Time, t/s

0 1

ITeach – Physics Form 4

2

3

4

5

Bab 2 Daya dan Gerakan

Menganalisis Graf Gerakan Graf Halaju - Masa

Menunjukkan bagaimana halaju bagi objek bergerak berubah dengan masa.

Contoh Halaju, v/ms-1 30

Pada masa, t = 4 s, halaju objek ialah 20 ms-1

25 20 15 10 5

Masa, t/s

0 1

ITeach – Fizik Tingkatan 4

2

3

4

5

Objek itu mengambil masa 3 saat untuk mencapai halaju 15 ms-1

Chapter 2 Force And Motion

Analysing Motion Graphs Determining Acceleration Velocity-Time Graph

Acceleration = gradient of the velocity-time graph

Example Velocity, v/ms-1

Acceleration = gradient of the velocity-time graph

30 25

acceleration =

20 15 10

=

20 4

=

5 ms-2

5

Time, t/s

0 1

ITeach – Physics Form 4

2

3

4

5

20 – 0 4–0

Bab 2 Daya dan Gerakan

Menganalisis Graf Gerakan Menentukan Pecutan – Graf Halaju - Masa

Pecutan = kecerunan graf halaju - masa

Contoh Halaju, v/ms-1

Pecutan = kecerunan pada graf halaju - masa

30 25

Pecutan

20

=

20 – 0 4–0

=

20 4

=

5 ms-2

15 10 5

Masa, t/s

0 1

ITeach – Fizik Tingkatan 4

2

3

4

5

Chapter 2 Force And Motion

Analysing Motion Graphs Determining Displacement Velocity-Time Graph The displacement of the object = area under the velocity-time graph

Example Displacement of the object from time, t = 4s to time, t = 9s, = area under the graph

Velocity, v

= area of shaded region

10

= 1 (10)(5) 2

4

ITeach – Physics Form 4

9

Time, t/s

= 25 m

Bab 2 Daya dan Gerakan

Menganalisis Graf Gerakan Menentukan Sesaran – Graf Halaju - Masa Sesaran objek = Luas di bawah graf halaju - masa

Contoh Sesaran objek daripada masa, t = 4s hingga masa, t = 9s, = luas di bawah graf

Halaju, v

= luas kawasan berlorek

10

= 1 (10)(5) 2

4

ITeach – Fizik Tingkatan 4

9

Masa, t/s

= 25 m

Chapter 2 Force And Motion

Analysing Motion Graphs

Summary Of Motion Graphs

Displacement-time graph

Velocity-time graph

Gradient

Velocity

Acceleration

Area under the graph

--------

Displacement

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Graf Gerakan

Ringkasan Graf Gerakan

Graf sesaran masa

Graf halaju - masa

Kecerunan

Halaju

Pecutan

Luas di bawah graf

--------

Sesaran

ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

2.3 Understanding Inertia

ITeach – Physics Form 4

Chapter 2 Force And Motion

Understanding Inertia Inertia – Object At Rest Inertia is a property of an object that causes it to resist any change to its state of motion.

An object that is at rest, will resist any effort to move it.

Example

Observation

When the cardboard is flicked, the coin will drop into the glass.

Coin at rest

Explanation

ITeach – Physics From 4

Cardboard flicked No cardboard support

The coin’s inertia will resist any effort to move it.

The coin stays in its original position.

Gravity causes the coin to fall into the glass.

Bab 2 Daya dan Gerakan

Memahami Inersia Inersia – Objek dalam keadaan rehat Inersia ialah kecenderungan objek menentang sebarang usaha untuk menggerakkannya daripada keadaan rehat.

Objek dalam keadaan rehat akan menentang sebarang usaha untuk menggerakkannya.

Contoh

Pemerhatian

Penerangan

ITeach – Fizik Tingkatan 4

Apabila kadbod ditarik, duit syiling akan jatuh ke dalam gelas.

Inersia syiling akan menentang Syiling dalam sebarang usaha untuk keadaan rehat menggerakkannya.

Kadbod ditarik

Syiling kekal pada kedudukan asalnya.

Tanpa sokongan kadbod

Graviti menyebabkan syiling jatuh ke dalam gelas.

Chapter 2 Force And Motion

Understanding Inertia Inertia –Object In Motion An object in motion will continue to move in a straight line unless acted upon by an external force.

Example

Observation

When the bus stopped abruptly, the passengers were thrown forward.

When the bus was moving

The passengers on the bus were also initially moving forward.

When the bus was stopped

The inertia of the passengers caused them to continue to move forward.

Explanation

ITeach – Physics From 4

Bab 2 Daya dan Gerakan

Memahami Inersia Inersia – Objek sedang bergerak Objek yang sedang bergerak akan terus bergerak dalam satu garis lurus kecuali ditindakkan oleh daya luar.

Contoh

Pemerhatian

Penumpang akan terhumban ke hadapan apabila bas yang sedang bergerak berhenti secara tiba-tiba.

Apabila bas sedang bergerak

Penumpang hadapan.

Apabila bas berhenti

Inersia menyebabkan penumpang terus bergerak ke hadapan.

juga

bergerak

ke

Penerangan

ITeach – Fizik Tingkatan 4

Chapter 2 Forces and Motion

Understanding Inertia Inertia And Mass – Object At Rest

The inertia of an object depends on its mass.

Mass

inertia

An stationary object with a higher inertia is harder to be moved than an object with a lower inertia.

Trolley full of things

Empty trolley

Smaller mass

Therefore lower inertia.

Hence it is easier to push an empty trolley.

ITeach – Physics From 4

Bigger mass

Therefore higher inertia.

Hence it is harder to push a trolley full of things.

Bab 2 Daya dan Gerakan

Memahami Inersia Inersia dan Jisim – Objek Dalam Keadaan Rehat

Inersia suatu objek bergantung kepada jisimnya.

Jisim

Inersia

Objek pegun dengan inersia yang tinggi adalah susah untuk digerakkan berbanding objek yang mempunyai inersia yang rendah.

Troli yang dipenuhi barang

Troli kosong

Jisim kecil

Inersia yang kurang

Lebih mudah untuk menggerakkan troli kosong.

ITeach – Fizik Tingkatan 4

Jisim yang besar

Inersia yang lebih tinggi

Lebih susah untuk menggerakkan troli yang dipenuhi barang.

Chapter 2 Forces and Motion

Understanding Inertia Inertia And Mass – Object In Motion A moving object with a bigger mass is more difficult to stop than an object with a smaller mass.

Example

Bicycle

Smaller mass

Therefore lower inertia.

Aero-plane

Bigger mass

Therefore higher inertia.

Hence it is easier to stop a moving Hence, it is more difficult to stop a bicycle. moving aero-plane.

ITeach – Physics From 4

Bab 2 Daya dan Gerakan

Memahami Inersia Inersia dan Jisim – Objek Sedang Bergerak Objek yang sedang bergerak dengan jisim yang besar adalah susah untuk diberhentikan berbanding objek yang mempunyai jisim yang kecil.

Contoh

Basikal

Jisim kecil Lebih mudah basikal.

ITeach – Fizik Tingkatan 4

Inersia rendah untuk

Kapal terbang

Jisim yang lebih besar

Inersia tinggi

menghentikan Lebih susah untuk menghentikan kapal terbang.

Chapter 2 Forces and Motion

Understanding Inertia Positive Effects Of Inertia – Tightening A Hammer Head

The head of a hammer can be tightened by hitting the handle on the floor.

Explanation

The hammer head and the handle moves when it is on its downward motion.

When handle touches the floor, the handle stops suddenly but the hammer head will continue to move downwards due to its inertia.

Hence the hammer head tightens.

ITeach – Physics From 4

Bab 2 Daya dan Gerakan

Memahami Inersia Kesan Positif Inersia – Mengetatkan Kepala Penukul

Kepala penukul boleh diketatkan dengan menghentak bahagian pemegangnya pada lantai.

Penerangan

Kepala penukul dan pemegangnya sedang bergerak apabila penukul dalam gerakan ke bawah.

Apabila pemegang menyentuh lantai, pemegang akan berhenti bergerak tetapi kepala penukul akan terus bergerak ke bawah disebabkan oleh inersia.

Maka, kepala penukul diketatkan.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces and Motion

Understanding Inertia Positive Effects Of Inertia – Drying An Umbrella

Droplets of water dislodges themselves form a spinning umbrella when the umbrella is stopped abruptly.

Explanation

When the umbrella is being spun, the droplets on the umbrella is in a state of motion.

When the umbrella is stopped suddenly, the water droplets continues to move forward due its inertia and dislodge themselves form the umbrella.

ITeach – Physics From 4

Bab 2 Daya dan Gerakan

Memahami Inersia Kesan Positif Inersia – Mengeringkan Payung

Titisan air hujan keluar dan jatuh daripada payung apabila payung yang sedang berpusing diberhentikan serta merta.

Penerangan

Titisan hujan pada payung dalam keadaan bergerak semasa payung berpusing.

Apabila payung berhenti berpusing secara tiba-tiba, titisan hujan akan terus bergerak ke hadapan disebabkan oleh inerisa dan titisan hujan keluar daripada payung.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces and Motion

Understanding Inertia Reducing The Negative Effects Of Inertia

Seat Belt

When a car stops suddenly, the inertia of the passenger will cause him to move forward.

The seat belt holds the passenger back, preventing the passenger form hitting the dashboard or the windscreen of the car.

ITeach – Physics From 4

Bab 2 Daya dan Gerakan

Memahami Inersia Mengurangkan Kesan Negatif Inersia

Tali Pinggang

Apabila sebuah kereta berhenti dengan tiba-tiba, penumpang akan bergerak ke hadapan disebabkan oleh inersia.

Tali pinggang mengelakkan penumpang terhumban ke hadapan.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces and Motion

Understanding Inertia Reducing The Negative Effects Of Inertia – Air Bag

Air Bag The airbag is either mounted under the dashboard of in the steering wheel.

The air bag will inflate automatically in the event of an accident.

The airbag prevents the car passengers from colliding with the dashboard or the steering.

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Bab 2 Daya dan Gerakan

Memahami Inersia Mengurangkan Kesan Negatif Inersia – Beg Udara

Beg Udara Beg udara diletakkan dibawah papan pemuka atau didalam stereng kereta.

Beg udara akan mengembang secara automatik ketika kemalangan berlaku.

Beg udara menghalang penumpang daripada terhentak pada papan pemuka dan stereng kereta.

ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

2.1Analysing Arah MataMomentum Angin 2.4

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Chapter 2 Forces and Motion

Analysing Momentum Definition Of Momentum Momentum is defined as the product of the mass of an object and its velocity. momentum = mass × velocity = mv Momentum is a vector quantity.

4 ms-1

2 ms-1

2 kg

4 kg

Momentum = mass × velocity

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Momentum = mass × velocity

= (2 kg)(4 ms-1)

= (4 kg)(- 2 ms-1)

= 8 kg ms-1

= - 8 kg ms-1

Bab 2 Daya dan Gerakan

Menganalisis Momentum Definisi Momentum

Momentum ditakrifkan sebagai hasil darab jisim dengan halaju.

Momentum = Jisim × Halaju = mv Momentum ialah kuantiti vektor.

4 ms-1

2 ms-1

2 kg

4 kg

Momentum = jisim × halaju

ITeach – Fizik Tingkatan 4

Momentum = jisim × halaju

= (2 kg)(4 ms-1)

= (4 kg)(- 2 ms-1)

= 8 kg ms-1

= - 8 kg ms-1

Chapter 2 Forces and Motion

Analysing Momentum Principle Of Conservation Of Momentum

The total momentum of colliding objects before collision is the same as the total momentum after collision.

The total momentum of colliding objects before collision

=

m1u1 + m2u2

=

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The total momentum after collision.

m1v2

+ m2v2

Bab 2 Daya dan Gerakan

Menganalisis Momentum Prinsip Keabadian Momentum

Jumlah momentum objek-objek sebelum pelanggaran adalah sama dengan jumlah momentum selepas pelanggaran jika tiada daya bertindak ke atas objek-objek yang berlanggar.

Jumlah momentum sebelum pelanggaran

=

m1u1 + m2u2

=

ITeach – Fizik Tingkatan 4

Jumlah momentum selepas pelanggaran

m1v2

+ m2v2

Chapter 2 Forces and Motion

Analysing Momentum Momentum – Example  An object, P, of mass 4 kg moving with a velocity of 5 ms -1 collides with an object, Q, of mass 2 kg moving with a velocity of 1 ms -1 in the opposite direction.  If after the collision, object P moving with a velocity of 3 ms -1 in the same direction, determine the velocity of object Q after collision.

Solution total momentum before collision = total momentum after collision mpup + mQuQ

= mpvp + mQvQ

(4)(5) + (2)(-1)

= (4)(3) + (2)(vQ)

20 – 2

= 12 + 2mQ

18

= 12 + 2mQ

2mQ mQ

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= 6 = 3 ms-1

Bab 2 Daya dan Gerakan

Menganalisis Momentum Momentum – Contoh  Suatu objek, P, dengan jisim 4 kg sedang bergerak dengan halaju 5 ms-1 berlanggar dengan objek, Q, yang mempunyai jisim 2 kg dan bergerak dengan halaju1 ms-1 pada arah bertentangan.  Jika selepas pelanggaran, objek P bergerak dengan halaju 3 ms-1 pada arah yang sama, hitungkan halaju objek Q selepas pelanggaran.

Penyelesaian Jumlah momentum sebelum = Jumlah momentum selepas pelanggaran pelanggaran mpup + mQuQ = mpvp + mQvQ (4)(5) + (2)(-1) 20 – 2

= 12 + 2mQ

18

= 12 + 2mQ

2mQ mQ

ITeach – Fizik Tingkatan 4

= (4)(3) + (2)(vQ)

= 6 = 3 ms-1

Chapter 2 Forces and Motion

Analysing Momentum Elastic Collision

Before collision Characteristics  Objects moves separately after collision. 

Total momentum is conserved.



Total kinetic energy is conserved.



Total energy is conserved.

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After collision

Bab 2 Daya dan Gerakan

Menganalisis Momentum Pelanggaran Kenyal

Sebelum pelanggaran

Selepas pelanggaran

Ciri-ciri  Objek bergerak berasingan selepas pelanggaran. 

Jumlah momentum diabadikan.



Jumlah tenaga kinetik diabadikan.



Jumlah tenaga diabadikan.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces and Motion

Analysing Momentum Inelastic Collision

Before collision

After collision

Characteristics  Objects stick to each other and move with a common velocity after collision. 

Total momentum is conserved.



Total kinetic energy after collision is less than total kinetic energy before collision.



Total energy is conserved.

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Bab 2 Daya dan Gerakan

Menganalisis Momentum Pelanggaran Tak Kenyal

Sebelum pelanggaran

Selepas pelanggaran

Ciri-ciri  Objek bergerak pelanggaran.

bersama

dengan

halaju

yang

sama

selepas



Jumlah momentum diabadikan.



Jumlah tenaga kinetik selepas pelanggaran kurang daripada jumlah tenaga kinetik sebelum pelanggaran.



Jumlah tenaga diabadikan.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces and Motion

Analysing Momentum Applications Of Momentum

The space shuttle lifting off

Tennis

Soccer ITeach – Physics From 4

A boy jumps forward, boat moves backwards

Bab 2 Daya dan Gerakan

Menganalisis Momentum Kegunaan Momentum

Roket bergerak ke atas

Tenis

Bola sepak ITeach – Fizik Tingkatan 4

Seorang budak lompat dari sebuah bot ke hadapan, bot bergerak ke belakang

Chapter 2 Forces And Motion

2.1 Arah Mata 2.5 Understanding TheAngin Effect Of Force

ITeach – Physics Form 4

Chapter 2 Forces And Motion

Understanding The Effect Of Force Effect Of Force

Force is a physical quantity that when acted on an object will cause the object to experience a change in •

Shape

•

Size

•

Speed

•

Direction of motion of an object

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kesan Daya Kesan Daya

Daya ialah kuantiti fizik yang boleh mengubahkan keadaan pegun atau gerakan seragam suatu objek apabila daya bertindak ke atas suatu objek.

•

Bentuk

•

Saiz

•

Laju

•

Arah objek yang bergerak

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding The Effect Of Force Balanced Forces When two of more forces acts on an object produces no nett force, then the forces are said to be balanced.

When balanced forces act on an object the object either

remains at rest

Example 1:

ITeach – Physics Form 4

moves with constant velocity

Example 2:

Example 3:

Bab 2 Daya dan Gerakan

Memahami Kesan Daya Daya-daya yang Seimbang Apabila dua atau lebih daya yang bertindak pada satu objek memusnahkan antara satu sama lain, daya paduan yang bertindak pada objek itu adalah seimbang.

Apabila daya-daya seimbang bertindak ke atas suatu objek, objek itu akan

kekal dalam keadaan rehat

Contoh 1:

ITeach – Fizik Tingkatan 4

Contoh 2:

Bergerak dalam kelajuan tetap

Contoh 3:

Chapter 2 Forces And Motion

Understanding The Effect Of Force Unbalanced Forces When two or more forces acting on an object are not balanced,

there will be a net force acting on the object.

Newton’s Second Law of motion

the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

•

The mathematical representation of Newton’s Second Law of Motion is

Fnet = ma

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kesan Daya Daya-daya yang Tidak Seimbang Apabila dua atau lebih dari dua daya daya yang bertindak ke atas suatu objek adalah tidak seimbang

Daya paduan bukan sifar

Hukum Gerakan Kedua Newton

Kadar perubahan momentum suatu objek adalah berkadar langsung dan dalam arah yang sama dengan daya paduan yang bertindak ke atasnya.

•

Hukum Gerakan Kedua Newton :

Fnet = ma

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding The Effect Of Force Example 1 20 N 4N Net force acting of object,

5 kg Fnet = 20 + 4 = 24 N to the right

According to Newton’s Second Law of Motion, Fnet = ma 24 = (5)a Therefore acceleration, a = 24/5 = 4.8 ms-2 Example 2 20 N

5 kg

Fnet = 20 – 4 = 16 N to the right According to Newton’s Second Law of Motion, Fnet = ma 16 = (5)a Therefore acceleration, a = 16/5 = 3.2 ms-2 ITeach – Physics Form 4

4N

Bab 2 Daya dan Gerakan

Memahami Kesan Daya Contoh 1 20 N 4N Daya paduan pada obejk,

5 kg Fnet = 20 + 4 = 24 N ke kanan

Mengikut Hukum Gerakan Kedua Newton Fnet = ma 24 = (5)a Pecutan, a = 24/5 = 4.8 ms-2 Contoh 2 20 N

5 kg

Fnet = 20 – 4 = 16 N ke kanan Mengikut Hukum Gerakan Kedua Newton, Fnet = ma 16 = (5)a Pecutan, a = 16/5 = 3.2 ms-2 ITeach – Fizik Tingkatan 4

4N

Chapter 2 Forces and Motion

Understanding The Effect of Force Application of Balanced and Unbalanced Forces Lift A man standing on a weighing scale in a lift.

R

Lift

There are 2 forces act on the system • •

The man’s weight, W (downward) Weighing machine

Normal reaction, R, act upward W

Situation

1 :

The lift stays stationary or moving with constant velocity

Situation 2 :

The lift accelerate upward with acceleration a.

Situation 3 :

The lift accelerate downward with acceleration a.

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kesan Daya Kegunaan Daya-daya Seimbang dan Tidak Seimbang Lif Seorang lelaki berdiri di atas mesin penimbang di dalam sebuah lif.

R

Lif

Terdapat 2 daya bertindak pada sistem • •

Berat lelaki, W (ke bawah) Mesin penimbang

Tindak balas normal, R, bertindak ke atas W

Situasi

1:

Lif pegun atau bergerak dengan halaju tetap.

Situasi 2 :

Lif memecut ke atas dengan pecutan a.

Situasi

Lif memecut ke bawah dengan pecutan a.

3 :

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

2.1 Arah Mata Angin 2.6 Understanding Impulse And Impulsive Force

ITeach – Physics Form 4

Chapter 2 Forces and Motion

Analysing Momentum Impulse Impulse is defined as the change of momentum of an object, that is

impulse = final momentum – initial momentum = mv - mu Example

before

4 ms-1

2 ms-1

2 kg

2 kg

impulse = final momentum – initial momentum = mv - mu = (2)(4) – (2)(2) = 8–4 = 4 kg ms-1

ITeach – Physics From 4

after

Bab 2 Daya dan Gerakan

Memahami Impuls dan Daya Impuls Impuls

Impuls ditakrifkan sebagai perubahan momentum suatu objek.

Impuls = Momentum akhir – Momentum awal = mv - mu Contoh

sebelum

4 ms-1

2 ms-1

2 kg

2 kg

Impuls = Momentum akhir – Momentum awal = mv - mu = (2)(4) – (2)(2) = 8–4 = 4 kg ms-1

ITeach – Fizik Tingkatan 4

selepas

Chapter 2 Forces And Motion

Understanding Impulse And Impulsive Force Impulsive Force

a strong force that acts within a short period of time between colliding objects.

is defined as the rate of change of momentum in a collision : Impulsive force , F = (mv – mu) ÷ t Examples where impulsive force is produced

Hitting nail with a hammer

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Hitting a baseball with a baseball bat

Car involved in an accident

Bab 2 Daya dan Gerakan

Memahami Impuls dan Daya Impuls Daya Impuls

Suatu daya kuat yang bertindak dalam jangka masa pendek antara objek-objek yang berlanggar.

Ditakrifkan sebagai kadar perubahan momentum dalam pelanggaran : Daya impuls , F = (mv – mu) á t Contoh-contoh daya impuls dihasilkan

Memukul paku menggunakan penukul ITeach – Fizik Tingkatan 4

Memukul bola besbol dengan pemukul bola besbol

Kereta terlibat dalam kemalangan

Chapter 2 Forces And Motion

Understanding Impulse And Impulsive Force Impulsive Force – Reducing The Impulsive Force

Large Large impulsive impulsive force force may may be be harmful, therefore in certain harmful, therefore in certain situations situations impulsive impulsive force force needs needs to to be be reduced. reduced.

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Impulsive Impulsive force force can can be be reduced reduced by by increasing increasing the the time time of of impact impact between between two two colliding colliding objects. objects.

Bab 2 Daya dan Gerakan

Memahami Impuls dan Daya Impuls Daya Impuls – Mengurangkan Kesan Daya Impuls

Daya Daya impuls impuls yang yang besar besar adalah adalah merbahaya, merbahaya, jadi jadi daya daya impuls impuls perlu perlu dikurangkan dikurangkan dalam dalam situasi situasi yang yang tertentu. tertentu.

ITeach – Fizik Tingkatan 4

Daya Daya impuls impuls boleh boleh dikurangkan dikurangkan dengan memanjangkan masa dengan memanjangkan masa pelanggaran pelanggaran antara antara objek-objek objek-objek yang yang berlanggar. berlanggar.

Chapter 2 Forces And Motion

Understanding Impulse And Impulsive Force High Jump – Reducing The Impulsive Force

•

A mattress is placed at the landing area in a high jump event.

•

When the high jumper lands on the mattress, the mattress compresses and increases the time taken for the high jumper to stop, thus increasing the time of impact and reducing the impulsive force.

•

This will prevent serious injury on the high jumper .

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Impuls dan Daya Impuls Lompat Tinggi – Mengurangkan Kesan Daya Impuls

•

Sebuah tilam diletakkan pada tempat mendarat dalam acara lompat tinggi

•

Apabila atlet mendarat pada tilam, tilam akan mampat dan memanjangkan masa bagi atlet untuk berhenti, jadi masa yang panjang semasa hentaman dapat mengurangkan daya impuls.

•

Ini dapat mengurangkan kecederaan atlet lompat tinggi.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Impulse And Impulsive Force Impulsive Force - Reducing The Impulsive Force

•

The bonnet of a car is soft and is able to crumple easily.

•

When a collision occurs, the bonnet gets crumpled and this increases the time taken for the car to stop (increasing the time of impact) thereby reducing the impulsive force on the car.

•

This will prevent the passengers of the car from suffering serious injuries.

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Bab 2 Daya dan Gerakan

Memahami Impuls dan Daya Impuls Daya Impuls – Mengurangkan Daya Impuls

•

Bonet kereta lembut dan mudah kemek.

•

Apabila pelanggaran berlaku, bonet menjadi kemek dan ini memanjangkan msa untuk kereta berhenti (memanjangkan masa pelanggaran). Masa pelanggaran yang panjang dapat mengurangkan daya impuls pada kereta.

•

Ini dapat menghalang penumpang kereta daripada mendapat kecederaan yang serius.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

2.1 Arah Mata Angin 2.7 Safety Features In Vehicles

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Chapter 2 Forces And Motion

Safety Features In Vehicles Importance Of Safety Features In A Car Safety features in cars are to reduce the damage to the cars and to reduce serious injuries to passengers caused by high impulsive force during collision.

Passenger safety case Rear crumple zone Headrests

Front Windscreen crumple zone Steering wheel

Seat belt Rear bumper Padded dashboardFront bumper

Front and Seat Windscreen Headrest bumper/Rear belt :rear Prevents :: Made crumple Hold bumper passengers shatter-proof the zones passenger : :To Easily from absorb glass serious back that soft Passenger Padded Steering dashboard wheel safety : Soft case :of Increases and : Frame easily time crumpled, of ofcrushed impact car is impact to preventing will neck reinforced increase not injuries. preventing break to theprotect easily time protect passenger damage of thus the impact reducing to for passengers being and injuries moving from to thus prevent reducing driver to impulsive from serious the force passengers injuries on passenger tohence inside the Front bumper/Rear bumper :car To absorb soft decreases the magnitude forward passengers injuries. due tothe inertia from crashing head injuries. orpreventing chest onto during dashboard. collision impact damage toofcarthe impulsive force.

Front bumper/Rear bumper : To absorb soft impact preventing damage to car Front and rear crumple zones : Easily crushed to increase time of impact and hence decreases the magnitude of the impulsive force.

Seat belt : Hold the passenger back preventing the passenger for being moving forward due to inertia Windscreen : Made of shatter-proof glass that will not break easily thus reducing injuries to passengers Headrest : Prevents passengers from serious neck injuries.

Passenger safety case : Frame of car is reinforced to protect the passengers from injuries.

Padded dashboard : Increases time of impact thus reducing impulsive force on passenger crashing onto the dashboard.

Steering wheel : Soft and easily crumpled, prevent driver from serious injuries to the head or chest during collision

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Ciri Keselamatan dalam Kereta Kepentingan Ciri Keselamatan dalam Kereta Ciri keselamatan dalam kereta dapat mengurangkan kerosakan kereta dan mengelakkan kecederaan yang serius pada penumpang yang disebabkan oleh daya impuls semasa pelanggaran.

Bamper depan/belakang : Untuk menyerap hentaman dan menghalang kerosakan kereta

Sarung keselamatan penumpang Zon remuk belakang Penahan kepala

Zon remuk hadapan Cermin depan Stereng kereta

Tali Bamper belakang pinggang Pad papan pemuka Bamper hadapan

Stereng kereta : Dibuat Lembut dan mudah Cermin Pad Penahan Sarung papan depan: keselamatan kepala: pemuka Menghalang : penumpang Meningkatkan daripada penumpang kaca : remuk, Bingkai masa tidak Zon Tali Bamper remuk pinggang depan/belakang depan : dan Memegang belakang : Untuk : Mudah penumpang menyerap remuk menghalang pemandu daripada mendapat berkecai hentaman daripada kereta dibuat yang kecederaan dan akan dengan mengurangkan mengurangkan dimasa kukuh leher. untuk daya kecederaan melindungi impuls untuk supaya hentaman memanjangkan penumpang dan menghalang tidak kerosakan pelanggaran terhumban kereta ke dan Bamper depan/belakang : Untuk menyerap kecederaan yang serius pada kepala atau penumpang. pada penumpang. penumpang daripada kecederaan. mengurangkan hadapan disebabkan impuls inersia.

Cermin depan: Dibuat daripada kaca tidak dada. hentaman dandaya menghalang kerosakan kereta Tali Sarung Stereng pinggang kereta keselamatan : : Lembut Memegang penumpang dan mudah penumpang : remuk, Bingkai Zon Penahan Pad remuk papan kepala: depan pemuka Menghalang dan : Meningkatkan belakang penumpang : Mudah masa berkecai yang akan mengurangkan supaya kereta menghalang dibuat penumpang pemandu dengan kukuh tidak daripada untuk terhumban mendapat melindungi ke remuk daripada hentaman kecederaan untuk dan mengurangkan memanjangkan di leher. daya impuls masa kecederaan penumpang. hadapan penumpang kecederaan disebabkan daripada yang serius inersia. kecederaan. pada daya kepala atau pelanggaran pada penumpang. dan mengurangkan impuls dada.

ITeach – Fizik Tingkatan 4

Zon remuk depan dan belakang : Mudah remuk untuk memanjangkan masa pelanggaran dan mengurangkan daya impuls Tali pinggang : Memegang penumpang supaya penumpang tidak terhumban ke hadapan disebabkan inersia.

Cermin depan: Dibuat daripada kaca tidak berkecai yang akan mengurangkan kecederaan penumpang.

Penahan kepala: Menghalang penumpang daripada kecederaan di leher.

Sarung keselamatan penumpang : Bingkai kereta dibuat dengan kukuh untuk melindungi penumpang daripada kecederaan.

Pad papan pemuka : Meningkatkan masa hentaman dan mengurangkan daya impuls pada penumpang.

Stereng kereta : Lembut dan mudah remuk, menghalang pemandu daripada mendapat kecederaan yang serius pada kepala atau dada.

Chapter 2 Forces And Motion

2.1 Arah Mata Angin 2.8 Understanding Gravity

ITeach – Physics Form 4

Chapter 2 Forces And Motion

Understanding gravity Acceleration Due To Gravity

All objects are able stay on the surface of the Earth or fall to the ground due to the gravitational force that pulls them towards the centre of the Earth.

Coconut falling from a coconut tree ITeach – Physics Form 4

Able to stay on surface of the earth

the

Satellite orbiting the earth

Bab 2 Daya dan Gerakan

Memahami Graviti Graviti

Semua objek dapat berdiri tegak di permukaan Bumi atau jatuh ke tanah disebabkan oleh daya graviti yang menarik semua objek ke pusat Bumi.

Buah kelapa jatuh dari pokok kelapa ITeach – FiziK Tingkatan 4

Manusia dapat berdiri di permukaan Bumi

Satellit mengorbit Bumi

Chapter 2 Forces And Motion

Understanding gravity Acceleration Due To Gravity Gravitational pull of the earth causes an object to accelerate at a constant rate as it falls.

The acceleration is known as the acceleration due to gravity, represented by the symbol ‘g’.

The acceleration due to gravity of the earth, g = 9.81 ms-2 (~ 10 ms-2).This means that the speed of a falling object increases by 10 ms-1 every 1 second as it falls to the surface of the earth.

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0 m/s → 10 m/s → 20 m/s →

0s 1s 2s

30 m/s →

3s

40 m/s →

4s

50 m/s →

5s

Bab 2 Daya dan Gerakan

Memahami Graviti Pecutan Disebabkan Oleh Graviti Tarikan daya graviti menyebabkan objek memecut pada kadar malar ketika objek bergerak jatuh ke tanah.

Pecutan ini dikenali sebagai pecutan graviti , diwakili oleh simbol ‘g’.

Pecutan graviti, g = 9.81 ms-2 (~ 10 ms-2). Laju bagi objek yang sedang jatuh ke permukaan Bumi meningkat sebanyak 10 ms-1 setiap 1 saat.

ITeach – Fizik Tingkatan 4

0 m/s → 10 m/s → 20 m/s →

0s 1s 2s

30 m/s →

3s

40 m/s →

4s

50 m/s →

5s

Chapter 2 Forces And Motion

Understanding gravity Weight Weight Weight of of an an object object is is defined defined as as the the gravitational gravitational force force that that acts acts on on the the object. object.

Weight, Weight, W W == mass mass ×× acceleration acceleration due due to to gravity gravity == mg mg Note Note :: To To calculate calculate the the weight weight of of an an object, object, the the mass mass must must be be measured measured in in kilogram kilogram while while the the acceleration acceleration due due to to gravity gravity in in units units of of ms ms-2-2 Example •

A boy of mass 55 kg have a weight of (55)(10) = 550 Newton

•

The weight of a 60 gram pencil is (60/1000)×(10) = 0.6 Newton

Note Note ::

The The acceleration acceleration due due to to gravity gravity on on the the surface surface of of the the moon moon is is 1/6 1/6 the the acceleration acceleration due due to to gravity gravity on on the the surface surface of of the the earth earth

The The acceleration acceleration due due to to gravity gravity on on the the moon moon is is about about 1.66 1.66 ms ms-2-2 ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Graviti Berat Berat Berat ialah ialah daya daya yang yang bertindak bertindak ke ke atas atas jisim jisim sesuatu sesuatu objek objek oleh oleh tarikan tarikan Bumi.

Bumi.

Berat, Berat, W W == Jisim Jisim ×× Pecutan Pecutan graviti graviti == mg mg Nota Nota :: Untuk Untuk mengira mengira berat berat sesuatu sesuatu objek, objek, jisim jisim mesti mesti dikira dikira dalam dalam kilogram kilogram dan dan pecutan pecutan graviti graviti dalam dalam unit unit ms ms-2-2 Contoh •

Seorang budak dengan jisim 55 kg mempunyai berat (55)(10) = 550 Newton

•

Berat bagi 60 gram pensel ialah (60/1000)×(10) = 0.6 Newton

Nota Nota ::

Pecutan Pecutan graviti graviti pada pada permukaan permukaan bulan bulan adalah adalah 1/6 1/6 daripada daripada pecutan pecutan graviti graviti di di permukaan permukaan Bumi.

Bumi.

Pecutan Pecutan graviti graviti di di permukaan permukaan Bulan Bulan ialah ialah 1.66 1.66 ms ms-2-2 ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding gravity The Differences Between Mass And Weight Mass, m

Weight, W

The amount of matter in an object

The gravitational force acting on an object

Base quantity

Derived quantity

S I Unit : kilogram

S I Unit : Newton

Scalar quantity

Vector quantity

Value is constant everywhere.

Value depends on the acceleration due to gravity.

Example

Example

An object of mass 10kg on earth An object weights 600 N on earth also has a mass of 10kg on the will only weigh 100N on the moon. moon.

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Graviti Perbezaan Antara Jisim Dengan Berat Jisim, m

Berat, W

Jumlah jirim yang ada dalam sesuatu Daya yang bertindak objek sesuatu objek

ke

atas

Kuantiti asas

Kuantiti terbitan

S I Unit : kilogram

S I Unit : Newton

Kuantiti skalar

Kuantiti vektor

Nilai tetap

Nilai bergantung kepada pecutan graviti.

Contoh

Contoh

Jisim suatu objek di Bumi ialah 10 Berat suatu objek di Bumi ialah 600 kg. Jisim objek itu di Bulan juga N. Berat objek itu di Bulan ialah 100 adalah 10 kg.

N.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

2.1 ArahForces Mata Angin 2.9 Analysing In Equilibrium

ITeach – Physics Form 4

Chapter 2 Forces And Motion

Analysing Forces In Equilibrium Forces In Equilibrium When the forces acting on an object is in equilibrium, then no net (resultant) force acts on the object.

The object will either be at rest (stationary) or moves with constant velocity.

Example

A pile book on a table

A car moving with constant velocity ITeach – Physics Form 4

A rifle hanging on a wall

An object resting on an inclined plane

Bab 2 Daya dan Gerakan

Menganalisis Daya - daya Keseimbangan Daya – daya Keseimbangan Apabila daya-daya yang bertindak pada suatu objek adalah seimbang, maka tiada daya paduan bertindak pada objek itu.

Objek itu akan berada keadaan rehat (pegun) bergerak pada halaju tetap.

Contoh

Buku-buku yang bertindih di atas meja

Kereta bergerak dengan halaju seragam ITeach – Fizik Tingkatan 4

Senapang digantung pada dindingl

Suatu objek dalam keadaan rehat pada satah condong

pada atau

Chapter 2 Forces And Motion

Analysing Forces In Equilibrium Forces In Equilibrium – Parallel Forces Two parallel forces are in equilibrium if the two forces have the same magnitude but act in opposite directions.

Examples driving force

frictional forces F

A car moving with T constant velocity The driving force and the frictional force are in equilibrium

An aeroplane cruising at constant velocity forward thrust T

Forward thrust and drag are in equilibrium ITeach – Physics Form 4

F drag

Bab 2 Daya dan Gerakan

Menganalisis Daya – daya Keseimbangan Daya – daya Keseimbangan – Daya – daya Selari Dua daya-daya selari adalah seimbang jika kedua-dua daya mempunyai magnitud yang sama tetapi bertindak pada arah yang berlainan.

Contoh

Daya geseran

Daya memandu Sebuah kerera bergerak dengan T halaju seragam Daya memandu dan daya geseran dalam keadaan seimbang

Sebuah kapal terbang bergerak pada halaju seragam

F seretan

Tujahan ke hadapan T

Tujahan ke hadapan dan seretan berada dalam keadaan seimbang ITeach – Fizik Tingkatan 4

F

Chapter 2 Forces And Motion

Analysing Forces In Equilibrium Forces In Equilibrium - Three Non-Parallel Forces The diagram below shows three forces P, Q and R acting in a system.

The three forces are in equilibrium.

Q P

30° 90° R

wall

wall A closed triangle will be obtained if the three forces are drawn end-to-end

Q R 30° P ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Daya – daya Keseimbangan Daya – daya Keseimbangan – Tiga Daya- daya Tidak Selari Rajah di bawah menunjukkan tiga daya P, Q dan R bertindak pada satu sistem.

Ketiga – tiga daya berada dalam keadaan seimbang.

Q P

30° 90° R

Dinding

Dinding Sebuah segitiga akan diperolehi jika garisan pada ketiga-tiga daya disambungkan

Q R 30° P ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Analysing Forces In Equilibrium Resultant Force – Parallelogram Of Forces

When two force P and Q acts on a object, the resultant force F, is represented by the diagonal of a parallelogram drawn using the forces P and Q. Example : The resultant of the forces P and Q can be obtained as shown

0

P

B

B A

Q 0

Q

P

0

P

Q

Q

P

P

B

C

0

C Q

θ P

A

If drawn to scale, the length of the diagonal OC represents the magnitude of the resultant force while the angle θ shows the direction of the resultant force.

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Daya-daya Keseimbangan Hasil Campur Daya-daya – Segiempat Selari

Apabila dua daya P dan Q bertindak pada suatu objek, hasil campur daya F, diwakili pepenjuru segiempat selari.

Contoh : Hasil campur daya-daya P dan Q boleh diperolehi seperti dibawah:

0

P

B

B A

Q 0

Q

P

0

P

Q

Q

P

P

B

C

0

C Q

θ P

A

Jika dilukis mengikut skala, panjang pepenjuru OC mewakili magnitud hasil campur daya-daya manakala sudut θ menunjukkan arah hasil campur daya-daya.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Analysing Forces In Equilibrium Resolution Of Forces

A force can be resolved into two components, that is, the two components, that is, the horizontal component, Fx, and the Vertical component, Fy

Fy = F sinθ F

θ Fx = F cosθ

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Daya-daya Keseimbangan Leraian Daya

Satu daya boleh dileraikan kepada 2 komponen iaitu

Komponen ufuk, Fx, dan Komponen tegak, Fy

Fy = F sinθ F

θ Fx = F cosθ

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Analysing Forces In Equilibrium Resolution Of Forces – Horizontal Component The horizontal component, Fx, is the “effective” force that moves the object in the horizontal direction.

Example

F = 550 N, rope boat 15° river

The force that moves the boat horizontally is the horizontal component of the force F = 500N That is, Fx = F cos 15° = (550)(0.9659) = 531.3N ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Menganalisis Daya-daya Keseimbangan Leraian Daya – Komponen Ufuk Komponen ufuk, Fx, adalah daya yang menggerakkan objek pada arah mengufuk.

Contoh

F = 550 N,

tali

bot 15° sungai

Daya yang menggerakkan bot secara mengufuk adalah komponen ufuk daya F = 500N Fx = F cos 15° = (550)(0.9659) = 531.3N ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

2.1 Work, Arah Mata Angin 2.10 Understanding Energy, Power And Efficiency

ITeach – Physics Form 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Work Done Work is a kind of energy transfer.

Work is done if an object acted upon by a force moves in the direction of the force.

Work done, W = applied force, F Ă— distance moved in the direction of the applied force, s

F

F s

Therefore work done, W = F s

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Kerja Dilakukan Kerja ialah satu jenis pemindahan tenaga.

Kerja dilakukan jika suatu objek bertindak melalui daya dan bergerak pada arah daya.

Kerja dilakukan, W = Daya, F Ă— sesaran dalam arah daya itu, s

F

F s

Kerja dilakukan, W = F s

ITeach – Fizik Tingkatab 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Work Done

If the applied force makes an angle θ with the direction of motion of the object, as shown

F

F θ

θ s

work done,W = horizontal component of the force × displacement work done, W = (F cosθ) (s) = Fs cosθ The unit of work is Newton meter (N m) of Joule (J)

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Kerja Dilakukan

Jika daya dikenakan membuat sudut θ pada arah objek bergerak, seperti dibawah:

F

F θ

θ s

Kerja dilakukan,W = Komponen ufuk daya × Sesaran Kerja dilakukan, W = (F kos θ) (s) = Fs kosθ Unit kerja ialah Newton meter (N m) atau joule (J)

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Examples Of Work Done

Pushing a shopping cart

Car barking. Work is done by the brakes.

Weightlifting ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Contoh Kerja Dilakukan

Kereta membrek. Kerja dilakukan oleh brek.

Menolak troli

Angkat berat ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Examples Of Work Not Done

The object that is acted upon by a force remains stationary.

Man pushing a wall

The direction of motion of the object is perpendicular to the applied force.

Waiter walking towards the diner

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Contoh Kerja Tidak Dilakukan

Objek yang ditindakkan oleh suatu kekal berada dalam keadaan pegun.

Seorang dinding

Arah pergerakan objek berserenjang dengan daya yang dikenakan.

Pelayan berjalan ke arah meja

ITeach – Fizik Tingkatan 4

lelaki

menolak

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Energy

Energy is the ability of an object to do work.

When work is done on an object, the object gains energy.

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Tenaga

Tenaga ialah keupayaan sesuatu objek untuk melakukan kerja.

Apabila kerja dilakukan pada suatu objek, objek mendapat tenaga.

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Kinetic Energy

Kinetic energy is the energy possesses by an object because of its motion.

This means that any object that moves have kinetic energy.

Examples

 a moving car  An electron orbiting an atom  A bowling ball rolling towards the bowling pins

The magnitude of the kinetic energy possessed by an object of mass m kilogram moving with a speed of v meters per second is

Kinetic energy = ½ m v2

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Tenaga Kinetik

Tenaga kinetik ialah tenaga yang disebabakan oleh gerakan.

Sebarang objek yang bergerak mempunyai tenaga kinetik.

Contoh

 Kereta yang sedang bergerak  Elektron mengorbit atom  Bola boling bergerak ke arah lorong boling

Tenaga kinetik bagi suatu objek dengan jisim m kilogram dan bergerak dengan laju v meter per saat diberi oleh formula

Tenaga Kinetik = ½ m v2

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Gravitational Potential Energy Potential energy is energy that is stored in an object

force displacement

Work is done

When work is done in lifting the box to a certain height above the ground, the box gains gravitational potential energy.

The gravitational potential energy of an object depends on its mass and its height above the ground.

Gravitational potential energy = mgh Where m = mass g = acceleration due to gravity h = vertical height of object above the ground ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Tenaga Keupayaan Graviti Tenaga keupayaan ialah tenaga yang diperoleh oleh suatu objek yang disebabkan oleh ketinggiannya dalam medan graviti.

Daya Sesaran

Kerja dilakukan

Kotak mendapat tenaga keupayaan graviti apabila kerja mengangkat kotak dilakukan hingga ke satu aras ketinggian di atas permukaan Bumi.

Tenaga keupayaan graviti bergantung kepada jisim dan ketinggian di atas permukaan Bumi.

Tenaga keupayaan graviti = mgh Dimana m = jisim g = pecutan disebabkan oleh graviti h =ketinggian objek di atas permukaan Bumi ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Elastic Potential Energy Elastic potential energy is the energy stored in an elastic object that is compressed or stretched.

A compressed spring stores energy

The stretched rubber band of the catapult stores energy

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Tenaga Keupayaan Kenyal Tenaga keupayaan kenyal ialah tenaga yang tersimpan dalam suatu bahan kenyal yang di dimampatkan atau diregangkan.

Spring yang dimampatkan mempunyai tenaga keupayaan kenyal

Gelang getah yang diregangkan mempunyai tenaga keupayaan kenyal

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Other Common Forms Of Energy

Chemical energy in a dry cell Heat energy Light energy Electrical energy Sound energy

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Bentuk Tenaga yang Lain

Tenaga kimia pada sel kering Tenaga haba Tenaga cahaya Tenaga elektrik Tenaga bunyi

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Principle Of Conservation Of Energy The amount of energy in the universe is constant.

Energy cannot be created nor it can be destroyed.

The Principle of Conservation of Energy states that energy can neither be created nor destroyed but energy changes from one form to another.

Examples: Chemical energy to light heat Gravitational potential energy to kinetic energy Gravitational potential energy to electrical energy

ITeach – Physics Form 4

Kuasa 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Prinsip Keabadian Tenaga Jumlah tenaga di alam semesta adalah tetap.

Tenaga tidak boleh dicipta atau dimusnahkan.

Prinsip Keabadian Tenaga menyatakan tenaga boleh berubah daripada satu bentuk ke bentuk lain tetapi tenaga tidak boleh dicipta atau dimusnahkan.

Contoh : Tenaga kimia ke tenaga haba Tenaga keupayaan kepada tenaga kinetik

graviti

Tenaga keupayaan kepada tenaga elektrik

graviti

ITeach – Fizik Tingkatan 4

Chapter 2 Forces And Motion

Understanding Work, Energy, Power And Efficiency Power Power, P, is the rate at which work is done or energy is transferred.

Power, P =

Work done, W or Energy, E Time taken,t

Power, P = E/t The unit of power is Joule per second (Js-1) or the Watt (W)

Example : An electric bulb rated 50 W used 50 Joules of electrical energy per second

ITeach – Physics Form 4

Bab 2 Daya dan Gerakan

Memahami Kerja, Tenaga, Kuasa dan Kecekapan Kuasa Kuasa, P, ialah kadar kerja dilakukan atau pemindahan tenaga.

Kuasa, P =

Kerja dilakukan, W atau Tenaga, E Masa diambil,t

Kuasa, P = E/t Unit bagi kuasa ialah Joule per saat (Js-1) atau Watt (W)

Contoh : Sebiji mentol elektrik pada kadar 50 W menggunakan 50 joule tenaga elektrik setiap satu saat.

ITeach – Fizik Tingkatan 4

Chapter 2 Force And Motion

2.11 Understanding Elasticity

ITeach – Physics Form 4

Chapter 2 Force And Motion

Understanding Elasticity

Elasticity

An object is said to be elastic if the object returns to its original shape when the force acting on it is removed.

Example

Spring

ITeach – Physics Form 4

Elastic Band

Bab 2 Daya dan Gerakan

Memahami Kekenyalan

Kekenyalan

Suatu objek dikatakan kenyal jika objek itu kembali ke bentuk asal apabila daya yang bertindak ke atas objek dialihkan.

Contoh

Spring

Tenaga keupayaan kenyal Spring mendapat tenaga keupayaan kenyal apabila ditekan atau diregang

pegun dimampat diregang ITeach – Fizik Tingkatan 4

Gelang getah

Chapter 2 Force And Motion

Understanding Elasticity Hooke’s Law

Hooke’s Law states that the extension of a spring is directly proportional to the stretching force that acts on it provided the elastic limit is not exceeded.

metre rule load

retort stand

ITeach – Physics Form 4

The elastic limit is the maximum force that can be applied to the spring before it ceases to be elastic.

Bab 2 Daya dan Gerakan

Memahami Kekenyalan Hukum Hooke

Hukum Hooke menyatakan pemanjangan spring adalah berkadar terus dengan daya yang dikenakan dengan syarat daya yang dikenakan tidak melebihi had kenyal.

Pembaris meter

Kaki retort

ITeach – Fizik Tingkatan 4

Beban

Had kenyal ialah daya pemanjangan maksimum yang boleh dikenakan ke atas spring sebelum spring menjadi tidak kenyal dan pemanjangannya menjadi kekal.

Chapter 2 Force And Motion

Understanding Elasticity Hooke’s Law Graph of applied force against extension

The graph of the stretching force against the extension produced by a spring

Point E : elastic limit F

P

E F = kx spring obeying spring not Hooke’s law obeying Hooke’s law

O ITeach – Physics Form 4

X

Line OE : Hooke’s law is obeyed. If the stretching force is removed, the spring will return to its original length.

Beyond E (E to P) Elastic limit is exceeded. If the stretching force is removed, the spring suffers permanent damage and will be deformed.

Bab 2 Daya dan Gerakan

Memahami Kekenyalan Hukum Hooke Graf Daya yang Dikenakan Melawan Daya Pemanjangan

Graf daya yang dikenakan melawan pemanjangan spring dihasilkan oleh spring

Titik E : Had kenyal F E F = kx spring mematuhi Hukum Hooke

O ITeach – Fizik Tingkatan 4

P

Spring tidak mematuhi Hukum Hooke

X

Garis OE : Hukum Hooke tidak dipatuhi. Jika daya yang dikenakan dialihkan, spring akan kembali ke panjang asal.

Melebihi E (E hingga P) Melebihi had limit. Jika daya yang dikenakan dialih, pemanjangan spring akan kekal dan spring akan rosak.

Chapter 2 Force And Motion

Understanding Elasticity Hooke’s Law The elastic constant or spring constant

ITeach – Physics Form 4

•

When Hooke’s Law is obeyed, the graph of applied force against extension is a straight line through the origin.

•

Hooke’s Law states that F = kx where k is the spring constant.

•

The gradient of the F-x graph gives the spring constant of the spring.

•

The higher the spring constant, the stiffer (less elastic) is the spring and vice versa.

Bab 2 Daya dan Gerakan

Memahami Kekenyalan Hukum Hooke - Pemalar spring

Daya, F / N

Pemanjangan spring, x / cm ITeach – Fizik Tingkatan 4

•

Apabila hukum Hooke dipatuhi, graf daya yang dikenakan melawan pemanjangan spring adalah suatu graf garis lurus.

•

Hukum Hooke menyatakan F = kx dimana k ialah pemalar spring.

•

Kecerunan graf F-x memberi nilai pemalar spring.

•

Semakin tinggi nilai pemalar spring, semakin tegang (kurang kenyal) spring dan sebaliknya.

Chapter 2 Force And Motion

Understanding Elasticity Factors Affecting The Elasticity Of A Spring

Factors

Stiff

Arrangement ofcoil Parallel Material Length used as spring Diameter of spring Large diameter material of Short Thin wire springs spring copper spring

FF

mF

F

ITeach – Physics Form 4

Less Stiff Series Long Small Thick diameter wire Steel spring

F

FF m

Bab 2 Daya dan Gerakan

Memahami Kekenyalan Faktor yang Mempengaruhi Kekenyalan Spring

Faktor

Tegang

Susunan spring Selari Bahan yang Panjang digunakan Pendek Diameter gegelung Diameter bahan spring Diameter Dawai nipis sebagai spring spring besar Spring kuprum

Bersiritebal Panjang Diameter Dawai kecil Spring besi

FF

mF

F

ITeach – Fizik Tingkatan 4

Kurang tegang

F

FF m

Chapter 2 Force And Motion

Understanding Elasticity Elastic Potential Energy

A stretched spring stores energy as elastic potential energy.

elastic potential energy stored in a spring.

F / N

= area under the Force against extension graph.

o

x / m

Ee =

ITeach – Physics Form 4

1 1 2 = Fx kx 2 2

Bab 2 Daya dan Gerakan

Memahami Kekenyalan Tenaga Keupayaan Kenyal

Spring yang diregangkan menyimpan tenaga sebagai tenaga keupayaan kenyal.

Tenaga keupayaan kenyal tersimpan dalam spring

F / N

=

o

x / m

Luas dibawah graf daya melawan pemanjangan spring.

Ee =

ITeach – Fizik Tingkatan 4

1 1 2 = Fx kx 2 2

Chapter 2 Force And Motion

Understanding Elasticity

Application Of Elasticity

Spring Mattress

ITeach – Physics Form 4

Shock absorber

Spring balance

Ammeter

Bab 2 Daya dan Gerakan

Memahami Kekenyalan

Aplikasi Kekenyalan

Tilam spring

ITeach – Fizik Tingkatan 4

Penyerap kejutan

Penimbang spring

Ammeter

The End

i - Teach