L5th - Sound

Sound and Light

Science ‐ Lower 5th Grade St. George's College November, 2008 1

Lower 5th A ‐ Sound and Light Name

Oral Intervention

Coin

Chocolate

Joaquin Mariano A. Victoria Melanie Alejandro Jose Fabrizio Joshua Edinson Hector Daniela Humberto Kymberly Alexandra Enzo Ariana Martin Mariano R. Stheffany Ana Caroline Bruno Rodrigo Sandra Maria Laura

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Brainstorming: What is similar between Sound and Light?

moves vibrates reflects range spectrum

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Lower 5th B ‐ Sound and Light Name

Oral Intervention

Coin

Chocolate

Carlos Anais Miguel Mariana Christopher Adriana Santiago Felipe Sol Gabriela Alexandra Valeria J. Eduardo Giosue Valeria P. Henry Alessio Sebastian Isabel Karen Erick Camila Bryan Jimena Arturo Maria Fernanda Diana Daniel Jesus Paola

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Brainstorming: What is similar between Sound and Light?

moves vibrates reflects range spectrum

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Objectives • Analyze how sounds are made.

• Recognize that sound energy can be carried from one place to another by waves.

• Recognize that sound travels at different speeds through different media.

• Describe how an echo forms.

• Explain what causes a sonic boom.

• Explain how light travels.

• Describe what can occur when light strikes an object.

• Describe what causes a rainbow.

• Explain how light and color are related.

Note: Most of the objectives will be covered in class, however the student must be responsible for those objectives not covered or concluded.

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Vocabulary Sound: a series of vibrations that you can hear.

Compression: the part of a sound wave in which air is pushed together.

Sound Wave: a moving pattern of high and low pressure that you can hear.

Amplitude: a measure of the strength of a sound wave; shown by height on a wave diagram.

Wavelength: the distance from one compression to the next in a sound wave.

Speed of sound: the speed at which a sound wave travels through a given material.

Echo: a sound reflection.

Sonic boom: a shock wave of compressed sound waves produced by an object moving faster than sound.

Reflection: the bouncing of light off an object.

Refraction: the bending of the path of light when it moves from one kind of matter to another.

Absorption: the stopping of light when it hits a wall or other opaque object.

Opaque: reflecting or absorbing all light; no image can be seen.

Translucent: allowing some light to pass through; blurry image can be seen.

Transparent: allows most light to pass through; clear image can be seen.

Prism: a solid object that bends light; not a lens.

Visible spectrum: the range of light that people can see.

Note: Most of the vocabulary words will be covered in class, however the student must be responsible for those words not covered or concluded.

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Lesson 1: What is Sound?

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Characteristics of Sound • Sound is vibrations that you can hear. An object vibrates to make sounds. This vibration causes particles in the air around the object to vibrate as well. You can see and feel the object vibrate, but not the particles in the air.

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Traveling Waves • The vibrations of a guitar string or a voice box, push and then pull the particles of air around them.

• As they push, they increase the pressure in the air.

• The area where air is pushed together is called a compression.

• As the vibrations pull, they decrease the pressure in the air.

• This results in alternating areas of high and low pressure in the air.

• Sound waves are quickly moving areas of high and low pressure.

• All sound is carried through matter as sound waves. Sound waves move out in all directions from a vibrating object.

• As the sound waves move away from their source of a sound, their energy is spread over a larger area.

• The farther you are from the source of a sound, the softer the sound will be.

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Waves • A wave is made out of rises and falls. The greatest distance that the water rises from its rest, or calm, position is called amplitude.

The more energy a wave carries, the greater its amplitude.

• Wavelength is the distance in a straight line from one place on a ripple to the same place on the next ripple.

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Hearing Sounds • We hear sound when waves reach our ears. Our ears take the sound waves and turn them into signals that go to our brain to be decoded.

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Lesson 3: How do Sound Waves travel?

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Speed of Sound • The speed at which a sound travels is called the speed of sound.

• Sound waves move at different speeds through different materials.

• In dry, cool air, sound waves travel 340 m/s.

• The speed of sound traveling through steel is 5200 m/s.

• In hard, solid materials, sound waves move very fast. This is because the particles in solids are close together and bump into each other often.

• In liquids, the particles don't bump into each other as often as in solids.

• In gases, sound waves move even more slowly, because the particles in gases are far more apart.

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Reflection • As sound waves travel through the air, an object such as a wall may be in their path.

• in this case, the sound waves hit the object and bounce, or reflect, off it. A sound reflection is called an echo.

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Sonic Booms • Some jet airplanes can fly faster than sound. Their powerful engines produce loud sounds. But, what happens to these sounds when the plane is moving faster than they are?

• An airplane traveling faster than sound makes sound waves that move away in all directions. But the airplane is moving faster than the sound waves, they are squeezed closer together.

• All the energy of the sound waves becomes one strong wave. This strong wave is called a shock wave.

• This shock wave or "boom‐boom" is called a sonic boom.

• Any object moving faster than sound makes such a shock wave.

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Sonic Boom

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