9J Gravity and Space ILU

Transcription

1 9J Gravity and Space ILU Level no. of qu.s Level 4 1. Lisa drew a picture of herself standing at four different positions on the Earth, A D B C not to scale (a) (i) Draw an arrow at each of the four positions to show the direction of the force of gravity on Lisa. The drawing at position A shows Lisa holding a ball on a string. Draw the ball and string in positions B, C and D. 1

2 (b) The drawing below shows: that the Earth goes round the Sun; that the Earth rotates on its axis. Earth Sun axis of the Earth orbit of the Earth not to scale Choose from the list below to answer parts (i) and. 60 seconds 60 minutes 24 hours 7 days 28 days 365 days (i) How long does it take for the Earth to go round the Sun once?... How long does it take for the Earth to rotate on its axis once?... Maximum 4 marks 2

3 Level 5 2. (a) In 2002 a large asteroid was discovered orbiting the Sun. It was named Quaoar. The diagram below shows Quaoar in four positions in its orbit. not to scale (i) In which of the four positions, A, B, C or D, is the effect of the Sun s gravity on Quaoar the greatest?... Explain your answer. On the diagram above, draw arrows to show the direction of the Sun s gravity on Quaoar in each of the positions A, B, C and D. 3

4 (iii) At which position, A, B, C or D, is Quaoar travelling most slowly?... Explain your answer. (b) The table below gives information about three of the planets in our solar system. planet average distance from Sun (millions of km) time for one orbit (Earth years) Average surface temperature of planet (ºC) Saturn Uranus Pluto (i) The time for one orbit of the planet Neptune is 165 Earth years. Estimate the average distance of Neptune from the Sun. Use information in the table to help you.... millions of km How does the surface temperature of these planets vary with distance from the Sun? Use information in the table to help you. (iii) Explain why the temperature varies with distance from the Sun in this way. maximum 6 marks 4

5 3. The picture shows a man called Aristotle. He lived in Greece over 2000 years ago. Aristotle said that the heavier an object is, the faster it will fall to the ground. (a) The drawings below show a bowling ball, a cricket ball and a ping-pong ball. Lila dropped them all at the same time from the same height. bowling ball cricket ball ping-pong mass=5 000 g mass=160 g mass=2.5 g If Aristotle was correct, which of the three balls would you expect to reach the ground first? Give the reason for your answer (b) Joe said that it would be a fairer test if Lila had only used a cricket ball and a hollow plastic ball as shown below. cricket ball mass = 160 g hollow plastic ball mass=56 g Why was Joe correct?

6 (c) About 400 years ago in Italy, a man called Galileo had a different idea. He said that all objects dropped from the same height would reach the ground at the same time. (i) Lila dropped a hammer and a feather at the same time from the same height. If Galileo was correct, which, if either, would reach the ground first? Gravity acts on both the hammer and the feather as they fall. Give the name of one other force which acts on them as they fall.... (iii) An astronaut on the moon dropped a hammer and a feather at the same time from the same height. How would the results of the astronaut s experiment on the Moon be different from Lila s experiment on the Earth? Explain your answer. 2 marks Maximum 6 marks 6

7 4. Satellites can sometimes be seen in the night sky. They look like stars slowly moving across the sky. (a) We can see stars because they are light sources. They give out their own light. Satellites do not give out their own light. Explain why satellites can be seen in the clear night sky marks (b) Sometimes a satellite suddenly stops being visible. However, you can usually see it again in another part of the sky later the same night. This can happen when there are no clouds in the sky and the satellite is overhead. Why does the satellite suddenly stop being visible? (c) Give one use of satellites in orbit around the Earth Maximum 4 marks 7

8 Level 6 5. The drawings show the mass and weight of four objects on different planets. Earth Mars Jupiter Venus 4 kg 6 kg 2 kg 4 kg 40 N 24 N 50 N 36 N (a) On which of the four planets is the object with the largest mass?... (b) How can you tell, from the drawings, that gravity is greater on Earth than on Venus? (c) Gravity is less on the Moon than on the Earth. Complete the sentences below to compare the weight and mass of an astronaut on the Moon and on the Earth. (d) The weight of an astronaut on the Moon is... the weight of an astronaut on the Earth. The mass of an astronaut on the Moon is... the mass of the astronaut on the Earth. The table below gives information about five planets. planet distance from the Sun (million km) time for planet to orbit the Sun (Earth-years) Venus Earth Mars 230 Jupiter Saturn

9 (i) Look at the information in the table. How does the time for a planet to orbit the Sun change with its distance from the Sun?.... Use information in the table to estimate the time for Mars to orbit the Sun.... Earth-years (e) The diagram below shows the path of a comet around the Sun. On the path of the comet below, place a letter X to show the position where the comet is travelling the fastest. path of comet Sun comet not to scale maximum 7 marks 9

10 6. The table shows the time taken for the Earth, Mars and Venus to orbit the Sun. planet time taken to orbit the Sun, in Earth years Earth 1.0 Mars 1.9 Venus 0.6 The diagram shows the orbits of the Earth, Mars and Venus round the Sun, at one particular time. The arrows show the direction in which the planets move. Sun Venus Earth Mars At the time shown in the diagram, the three planets were lined up with the Sun. not to scale (a) Show the position of the Earth three months after the planets were lined up, by marking a point on the Earth s orbit. Label the point E. 10

11 (b) (i) Show the approximate position of Mars three Earth months after the planets were lined up, by marking a point on Mars s orbit. Label the point M. Explain why Mars is in this position. (c) (i) Show the approximate position of Venus three Earth months after the planets were lined up, by marking a point on Venus s orbit. Label the point V. Explain why Venus is in this position. Maximum 5 marks 7. The diagram shows the orbits of the Earth, Mars and Venus. The position of the Earth is shown. Sun orbit of Venus Earth orbit of the Earth orbit of Mars not to scale A person on the Earth observes Mars and Venus. 11

12 (a) (i) On the diagram above, draw two more dots to show the positions of Mars and Venus when they are closest to the Earth. Label the dot for Mars with a letter M and the dot for Venus with a letter V. Why is it easiest to see Mars when it is closest to the Earth? (b) What force keeps the Earth in its orbit and stops it flying off into space?..... (c) From the Earth, the Moon always looks approximately the same size. What can you conclude from this about the orbit of the Moon around the Earth? (d) The diagram shows the Earth in its orbit around the Sun. N Sun Britain S not to scale What season is it in Britain? Explain your answer marks Maximum 6 marks 12

13 8. In July 1994, fragments of the comet Shoemaker-Levy 9 were pulled into the planet Jupiter, causing a series of enormous collisions. (a) The fragments of comet were pulled towards Jupiter by gravity. How did the gravitational force vary with the mass of the fragment? (b) As each fragment approached Jupiter, the gravitational force on it changed. Describe the change (c) Tick the correct box to complete the statement. Between the different fragments of the comet there was an attractive force there was a repulsive force there was no force The comet was in fragments because, in July 1992, it had passed very close to Jupiter and had broken up. 13

14 (d) Tick the correct box to describe the gravitational force per kilogram on different sides of the comet as it passed close to Jupiter. all parts of the comet were pulled towards Jupiter equally strongly all parts of the comet were pulled towards Jupiter, but the side facing towards the planet was pulled more strongly all parts of the comet were pulled towards Jupiter, but the side facing away from the planet was pulled more strongly the side of the comet facing towards Jupiter was pulled towards the planet but the side facing away was repelled (e) Tick the correct box to show what gravitational force (if any) the comet exerted on Jupiter. no force an attractive force a repulsive force Maximum 5 marks 14