METHOD CONCEPT / EDITOR
Boom voortgezet onderwijs
AUTHORS
Sjef Buil
Freek Hoogeveen
Peter Koopmans
Elout Roeland
Donald Staal
Paul Stoop
Arjen Wielemaker
Michel Wijnhold
POLARIS
PHYSICS + CHEMISTRY
HAVO / VWO
YEARS 1–2
BOOM VOORTGEZET ONDERWIJS
Contents
1 Light
1.1 Seeing and colours 8
1.2 Shadow 14
1.3 Mirrors and lenses 20
1.4 Lens and image 26 1.5 The eye 32
Test preparation 38
2 Motion
2.1 Speed and average speed 42
2.2 Calculating speed 48
2.3 Acceleration and deceleration 54
2.4 Distance-time graph 60
2.5 Braking distance and reaction time 66
Test preparation 72
3 Substances
3.1 Substances and substance properties 76
3.2 Density 82
3.3 The building blocks of substances 88
3.4 Phase transitions 94
3.5 Separating mixtures 100
Test preparation 106
4 Electricity
4.1 Electric charge and voltage 110
4.2 Electric current 116
4.3 Electrical circuits 122
4.4 Energy and power 128
4.5 Electricity and safety 134
Test preparation 140
5 Heat
5.1 Heat and temperature 144
5.2 Heat transfer 150
5.3 Burning and extinguishing 156
5.4 Chemical reactions 162
5.5 Climate change 168
Test preparation 174
6 The universe
6.1 Earth and the Sun 178
6.2 Earth and the Moon 184
6.3 The Solar System 190
6.4 Stars 196
6.5 Galaxies 202
Test preparation 208
Reference
A Practicals
A1 Safety 212
A2 Measuring 212
B Graphs
B1 Reading graphs 214
B2 Making graphs 215
C Calculation
C1 Prefixes 216
C2 Powers of ten 216
C3 Converting units 217
C4 Converting compound units 217
C5 Equations 218
C6 Calculating with equations 220
D Research 222
E Design 224 Image credits 226 Register of terms 227
6 The Universe
6.1 Earth and the Sun 178
6.2 Earth and the Moon 184
6.3 The Solar System 190
6.4 Stars 196
6.5 Galaxies 202
Test preparation 208
6.1 Earth and the Sun
GOAL You learn how the Sun affects Earth.
Earth and the Sun Earth is a planet (Figure 6.1). Its circumference is 40,000 km, and its diameter is nearly 13,000 km. Mercury, Mars and Jupiter are also planets. Planets move around the Sun in large, almost circular orbits. Earth orbits at a distance of 150 million km from the Sun. The Sun is a star, and much larger than Earth. The Sun is almost 1.5 million km across, more than 100 times Earth’s diameter. These sizes and distances are so gigantic, it’s hard to imagine them. It helps to compare them with more familiar things. If the Sun were the size of a large orange, Earth would be a pinhead about 10 metres away. Between Earth and the Sun and beyond exists mainly empty space. Stars other than the Sun are so far away that you only see them as small points of light in the sky.
Day and night The Sun illuminates Earth. The side of Earth facing the Sun is illuminated, so it is daytime there. It is dark on the other side of Earth, so it is night in this area. Day and night are the result of Earth turning on its axis. This is an imaginary axis that passes through the North Pole and the South Pole (Figure 6.2). Earth turns eastward on its axis once every 24 hours. This is called a solar day. The Sun rises in the east in the morning and sets in the west in the evening.
Earth’s axis North Pole
South Pole
6.2 Earth’s axis of rotation
6.1 Earth from space
6.3 Why summer and winter exist
Summer and winter Earth not only revolves on its own axis, it also orbits the Sun. One orbit around the Sun takes 365 days; a year. Figure 6.3 shows that Earth’s axis is not at right angles to its orbit around the Sun, and Earth’s axis is always tilted in the same direction. As a result, the time from sunrise to sunset changes during the year, and the Sun is not as high in the sky all year round. This creates the four seasons: spring, summer, autumn and winter. It is summer in the Netherlands when Earth’s northern hemisphere is tilted towards the Sun (position of Earth on the left in Figure 6.3). The area around the North Pole then faces the Sun 24 hours a day, so it doesn’t get dark there at all. In the Netherlands, the Sun is high in the sky during the day and the days are long. It is winter in the Netherlands when Earth’s southern hemisphere is tilted towards the Sun (position of Earth on the right in Figure 6.3). The Sun in the Netherlands is then low in the sky during the day, and the days are short. In summer, more sunlight reaches each square metre of the surface (Figure 6.4). Because the days are longer, this part of Earth is then heated for longer each day. As a result, it is hotter in summer than in winter.
6.4 Difference in light incidence between summer and winter
1 a How long does it take Earth to orbit the Sun? R
b What is a solar day? R
2 What causes the alternation of day and night? Choose the correct answer: R
A Earth going around the Sun.
B The rotation of Earth on its axis.
C The tilt of Earth’s axis.
3 a Earth’s axis is not at right angles to Earth’s orbit around the Sun, and is always tilted in the same direction. Write down two consequences of this. R
b Explain in your own words what causes summer and winter. T1
4 Earth turns on its axis, and you rotate with it.
a How long does it take Earth to orbit the Sun? R
b The circumference of Earth at the equator is about 40,000 km. Calculate how fast Earth is turning at the equator. T1
c Explain why this speed is 0 m/s at the North Pole. T2
d Work out what this speed is in the Netherlands. I
5 Jupiter is 778 million km from the Sun. If you imagine the Sun as an orange with a diameter of 10 cm, Earth is at a distance of 10.8 m.
a How far is Earth from the Sun? R
b Calculate how far Jupiter would be from the Sun on this scale. T1
c On this scale, Earth has a diameter of less than 1 mm. Explain how you would calculate this answer yourself. T2
6 If you wanted to see the Sun rise over the sea in England, would you go to the east coast or the west coast? T1
7 Figure A
The figure shows a map of the Netherlands with coordinates. To indicate a position, Earth is divided up by lines of longitude and latitude. A line of longitude on the map is vertical and a line of latitude is horizontal. The map shows that Apeldoorn is at 6 degrees of longitude. London is at 0 degrees. The map shows that Arnhem is at 52 degrees of latitude. The equator is at 0 degrees of latitude.
a Explain whether the Sun rises earlier in Arnhem or in The Hague. T2
b Explain why the Sun rises 1 hour earlier if you travel 15 degrees east. T2
c Calculate how many minutes earlier the Sun rises in Apeldoorn than in Amsterdam. T1
8 a Give two reasons why it is colder in the Netherlands in winter than in summer. T1
b Explain why it is winter in the Southern Hemisphere when it is summer in the Netherlands. T1
9 In the area around the North Pole, the Sun shines 24 hours a day in the summer.
a Use a drawing to show how this is possible. T2
b Even when the Sun shines 24 hours a day, it remains cold at the North Pole. Give the reason for this. T2
10 Worksheet 6.10
Figure 6.3 shows Earth in two positions. On the left it is 21 June, the longest day of summer in the Netherlands. On the right it is 21 December, the shortest day of winter in the Netherlands.
a On your worksheet, draw the position of Earth on 21 March, the first day of spring. T1
b Also draw the position of Earth on 21 September, which is the first day of autumn. T1
c Explain why on these two days, day and night are of equal length almost everywhere. T2
d Explain why the days and nights in countries around the equator last approximately the same throughout the year. I
HOME EXPERIMENT
Hold a stick vertically on a sheet of paper. Measure the length of the shadow at three different times during the day. What do you notice about the length and direction of the shadow?
Arnhem
The Hague
Apeldoorn
Leeuwarden
Maastricht
Apply what you have learned
11 Read the text opposite about wine growing in Northern Europe.
a What’s the advantage of steep vineyards in northern regions? T1
b Why are north-facing slopes unsuitable for wine growing? T2
c In what part of the world would northfacing slopes be suitable for wine growing? I
d Why aren’t very steep slopes suitable for wine growing in countries close to the equator? Use a drawing to explain your answer. T2
e What’s the advantage of climate change for wine growing in the Netherlands? I
12
The rate at which Earth turns on its axis is slowly decreasing. Research has shown that 600 million years ago, Earth turned on its axis in only 22 hours. Calculate how many days there were in a year then. I
13 Figure B
Mercury’s axis of rotation is at right angles to its orbit around the Sun.
Explain why this determines whether summer and winter exist on Mercury. T2
14 Figure C
The planet Uranus orbits the Sun once every 84 years. and turns on its axis in about 17 hours. Unusually, its axis of rotation almost lies in the plane of its orbit around the Sun. Explain the effect of the axis of rotation on the length of the days and seasons on Uranus. I
Have you achieved the learning goal?
R I know the meaning of the following terms:
Earth and the Sun
Day, night and solar day
Summer and winter
T1 I can describe what causes day and night and summer and winter on Earth.
T2 I can explain how the tilt of a planet’s axis of rotation affects the length of a day on the planet, and why seasons exist.
I I can explain how latitude affects the amount of solar heat that falls on the surface.
Uranus
Wine growing in Northern Europe Wine is made from grapes. Grapes need lots of sun to grow well, which is why lots of wine is made in southern European countries such as France and Italy. Countries further north, such as the Netherlands and Germany, also have vineyards. These vineyards are often planted on steep slopes so that the grapes get more sunlight. The slopes alongside the river Moselle in Germany are a good example of this (Figure 6.5). The further north you go, the lower the Sun is in the sky. The amount of solar heat per square metre on the surface is therefore lower in the north (see also Figure 6.4). On a steep south-facing slope, however, there is more sunlight per square metre (see Figure 6.6).
6.6 When the Sun is low, there is more sunlight per square metre on a steep, south-facing slope than on flat land.
6.5 Wine growing along the river Moselle near Trittenheim, Germany
6.2 Earth and the Moon
GOAL You learn that the Moon’s motion around Earth is caused by gravity, and that it explains the lunar phases.
The Moon The Moon is much smaller than the Sun. Because the Moon is much closer to Earth than the Sun, these celestial bodies look the same size in the sky. The average distance between Earth and the Moon is 380,000 km. The Moon’s diameter is 3,500 km, so it’s much smaller than Earth. It moves in an almost circular orbit around Earth that takes nearly a month. The Moon, like Earth, is illuminated by the Sun, so the light you see from the Moon in the sky is reflected sunlight.
Lunar phases The Moon’s orbit around Earth is in almost the same plane as Earth’s orbit around the Sun. The Moon, like the Sun, rises in the east and sets in the west. Only that part of the Moon that is illuminated by the Sun is visible, the other side is not visible. This results in various appearances of the Moon that are called the lunar phases (Figure 6.8). The phase when the Moon is in the sky at the same time as the Sun and the Sun is shining on the far side of the Moon is called new moon. The Moon is then not visible from Earth. A week later, a half-moon is visible when the right side of the Moon is illuminated when observed from Earth. This phase is called first quarter. A week later a full moon can be seen when the illuminated side of the Moon is facing Earth. The Moon then rises as the Sun sets. The next phase a week later is called last quarter, when the left side of the Moon is illuminated when observed from Earth.
6.7 American astronaut Buzz Aldrin on the Moon, 20 July 1969
6.8 The lunar phases (sizes and distances are not to scale)
Gravity If you throw something upwards, it falls down again. This is due to gravity. It isn’t just Earth that attracts objects; all objects attract each other. This force is only noticeable when the objects are very large and heavy, such as stars and planets. Earth is very large and heavy, so you can easily feel its gravitational pull. That is the force that pulls you to the ground and prevents you from floating away into space.
The force of gravity gets weaker as the distance between the objects increases. Even at a distance of 380,000 km, however, Earth’s gravity is strong enough to attract the Moon. If Earth attracts the Moon, why doesn’t it fall to Earth’s surface? This can be explained as follows. Figure 6.9 shows a cannon on top of a very high mountain. If the cannonball is fired, it will fall to Earth along a curved trajectory. The faster the speed of the cannonball, the further it gets. Earth is round, so the cannonball falls further and further around Earth. If the cannonball is fired at sufficient speed, it will never hit the ground but orbit Earth. This is exactly what’s happening with the Moon; it’s moving fast enough to orbit Earth. Satellites also orbit Earth.
6.9 A shot around Earth
Practice
15 a How long does it take for the Moon to orbit Earth? R
b The Sun is a direct light source, the Moon is an indirect light source. Explain the difference. T1
c What are the four lunar phases? R
d What force causes something to fall to Earth? R
16 It is half moon. The right side of the Moon is illuminated.
a Explain whether it is first quarter or last quarter. T2
b Explain why the Sun has just set or is setting at this moment. T2
c During a solar eclipse, the Moon is exactly between Earth and the Sun. Explain which lunar phase is associated with a solar eclipse. T2
d During a lunar eclipse, Earth is between the Sun and the Moon. Explain which lunar phase is associated with a lunar eclipse. T2
17 Figure A
Figure A shows two lunar phases. For both lunar phases, explain where the Moon is at that moment. Choose from the answers below. T1
A Between new moon and first quarter.
B Between first quarter and full moon.
C Between full moon and last quarter.
d Between last quarter and new moon.
18 We always see the same side of the Moon from Earth.
a Explain why this is only possible if the Moon also rotates on its axis. Tip: it helps if you play out the movements of the Moon and Earth with a fellow student. T2
b The side of the Moon invisible from Earth is sometimes called the Dark side of the Moon. Why is this name incorrect? T1
c About how long is a lunar day? T2
19 You can measure the distance to the Moon by bouncing a laser beam off a mirror which was left on the Moon by American astronauts. By measuring the time between sending and receiving the laser beam, the distance can be measured with an accuracy of a few millimetres.
The speed of light is exactly 299,792 km/s. A laser beam used to measure the distance to the Moon is reflected and returns 2.548 seconds later. Use this result to calculate the distance to the Moon. T2
HOME EXPERIMENT
Hold a tennis ball with your arm outstretched in front of you in a room lit only by a lamp directly in front of you. Describe what you see on the tennis ball as you turn around.
20 The force of gravity on the Moon is six times weaker than on Earth.
a Explain whether you can lift a mass of 200 kg on the Moon. T1
b What does a weighing scale on the Moon read when you put this mass on it? T2
c Explain whether you can beat the high jump world record on the Moon. T2
21 Figure B
A satellite orbiting Earth at an altitude of 36,000 km orbits every 24 hours, just like Earth. If the satellite orbits directly above the equator, it will stay above the same spot on Earth. This is called a geostationary satellite.
a Why can a satellite only have a geostationary orbit above the equator and not over the poles? T2
b Why are geostationary satellites useful for communications? T2
c For satellite TV, you need a satellite dish. which receives signals from a geostationary satellite. Explain why you need to point the antenna to the south. T1
22 Figure C
Polar satellites orbit Earth’s poles at a much lower height of up to about 1,000 km. These satellites orbit Earth much faster than geostationary satellites.
a Think of a reason why a polar satellite has to move faster than a geostationary satellite. T2
b Polar satellites are used to create maps, among other things. Give two reasons why polar satellites are better suited for this than geostationary satellites. I
Apply what you have learned
23 Read the text opposite about weightlessness.
a Explain why the astronauts in the Inter national Space Station (ISS) are weightless. T1
b Why doesn’t the ISS fall to Earth? T2
c Explain what a weighing scale in the ISS would read if an astronaut stood on it. T2
d Is the gravity acting on an astronaut in the ISS less, greater than or equal to the gravity acting on the astronaut on Earth’s surface? Explain your answer. I
24 In the film Apollo 13, Tom Hanks floats in a manned spacecraft. Despite this, the actor has never actually been in space. The scenes were shot on a film set on board a large plane. This plane flew at a steep angle to a high altitude, then the pilot put the plane into freefall.
a What is the effect of the freefall for the occupants of the plane? T1
The film is about the Apollo 13 flight to the Moon. The Apollo spacecraft was launched on a three-stage rocket used for missions to the Moon in the 1960s and 1970s. The rocket, which was more than 100 m tall, was almost entirely filled with fuel. The fuel was used to overcome the gravitational pull of Earth.
b Such a large rocket is not needed for getting back to Earth from the Moon. Explain why. T2
25 The ISS orbits Earth in 1.5 hours at 355 km above the surface. Earth’s radius is 6,371 km.
a Calculate the distance from the ISS to the centre of Earth. T1
b Calculate the distance the ISS travels in 1.5 hours. Use the equation for the circumference of a circle: O = 2π r T2
c Calculate the speed at which the ISS moves around Earth. T2
d Explain what would happen if the ISS slowed down. T2
Have you achieved the learning goal?
R I know the meaning of the following terms:
The Moon
Lunar phases
Gravity
T1 I can describe how the Moon moves around Earth, and use this to explain the lunar phases.
T2 I can explain that the speed of a satellite depends on the height of its orbit above Earth.
I I can explain what weightlessness is.
Weightless The International Space Station (ISS) orbits Earth at about 355 km above Earth’s surface. Due to the gravitational pull of Earth, the ISS continues to circle Earth. One orbit takes about an hour and a half. In the ISS, all objects, including the astronauts, are weightless. Everything that is not firmly attached floats around freely (Figure 6.10), because everything in the ISS is falling just as fast as the ISS itself.
It’s comparable with being in a lift when the cables break. If you’re in the lift, gravity makes you fall as fast as the lift. Within the lift, you seem to float because you no longer feel the floor. The ISS also falls under the effect of gravity, with the difference being that it’s also orbiting Earth.
6.10 Astronaut Peggy Whitson floats through the ISS.
© 2020 Boom voortgezet onderwijs, Groningen, The Netherlands
Subject to the exceptions set forth in or pursuant to the Copyright Act (Auteurswet) of 1912, nothing in this publication may be reproduced, stored in an automated database or published in any form or by any means, whether electronic, mechanical by photocopying, recording or in any other way, without prior written permission from the publisher.
To the extent that making copies of this publication is permitted pursuant to Articles 16h to 16m of the Auteurswet (Dutch Copyright Act) 1912 in conjunction with the Decree of 27 November 2002, Netherlands Official Gazette 575, the statutory compensation must be paid to Stichting Reprorecht in Hoofddorp (P.O. Box 3060, 2130 KB Hoofddorp, the Netherlands) or the publisher must be contacted to agree a settlement within the meaning of Article 16l, paragraph 5 of the Auteurswet of 1912. For the reproduction of part or parts of this edition in anthologies, readers or other compilation works (Article 16 Auteurswet 1912), contact Stichting PRO (Stichting Publicatie- en Reproductierechten, P.O. Box 3060, 2130 KB Hoofddorp, the Netherlands, www.stichting-pro.nl).
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, recording or otherwise without prior written permission of the publisher.
ISBN 978 94 9311 361 9 www.boomvoortgezetonderwijs.nl
Polaris is an RTTI-certified teaching method and distinguishes four types of questions:
r Reproduction questions
t1 Training-related application questions
t2 Transfer-related application questions
i Insight questions
For more information about the RTTI system, see www.docentplus.nl.
Translation
Paul Smith
Richard Purdom
Marjan Borger (Easy Translation)
Book design & technical drawings
René van der Vooren, Amsterdam
Image editing
Roel Kooister, Amsterdam
René van der Vooren, Amsterdam
Image purchasing
Imago Mediabuilders, Amersfoort
Printing & binding Wilco, Amersfoort