Which list correctly orders these three objects from smallest to largest?
A) Moon, Earth, Sun
B) Sun, Earth, Moon
C) Earth, Moon, Sun
D) Moon, Sun, Earth
2
Answer the following questions about objects in space.
(a)What is a star?(1)
(b)What is a planet?(1)
(c)What is a natural satellite?(1)
3
Complete the sentences below using words from the box. Each word may be used once, more than once, or not at all. Word box: gravity, orbit, mass, weaker, stronger, weight The Moon stays in ______ (i) around the Earth because of the force of ______ (ii) between the Earth and the Moon. The size of this force depends on the ______ (iii) of the two objects, and it gets ______ (iv) as the distance between the Earth and the Moon increases.
(4)
4
The Earth experiences a cycle of day and night.
(a)State the reason the Earth experiences a cycle of day and night.(1)
(b)Explain why one side of the Earth has day while the other side has night at the same time.(1)
5
The Earth's axis is tilted, which causes the UK to have seasons.
(a)State the approximate angle of the Earth's axial tilt.(1)
(b)Explain why the tilt of the Earth's axis causes the UK to have summer and winter.(2)
6
A student models the Earth's day-night cycle using a lamp (representing the Sun) and a globe on a spindle (representing the Earth), in a darkened room.
(a)Identify which part of the model represents the Sun, and which part represents the Earth.(1)
(b)The student spins the globe on its spindle while the lamp stays still. Explain how this models day and night on Earth.(2)
(c)Suggest one way this model does not accurately represent the real Earth-Sun system.(1)
7
The diagram shows four positions (A, B, C and D) of the Moon as it orbits the Earth, viewed from above. Position A is directly between the Earth and the Sun. Position C is directly on the opposite side of the Earth from the Sun. Positions B and D are each a quarter of the way around the orbit from A.
(a)Name the phase of the Moon seen from Earth when the Moon is at position A.(1)
(b)Name the phase of the Moon seen from Earth when the Moon is at position C.(1)
(c)Explain why we see different phases of the Moon during a month, even though the Moon itself does not change shape.(2)
8
A solar eclipse and a lunar eclipse are both caused by the Sun, Earth and Moon lining up.
(a)State the conditions needed for a solar eclipse to occur.(2)
(b)The Moon orbits the Earth once about every month, passing between the Earth and the Sun each time. Explain why a solar eclipse does not happen every month.(2)
9
A student investigates how the height a marble is dropped from affects the diameter of the crater it makes in a tray of flour, to model meteorite impacts on the Moon's surface. The table below shows the mean crater diameter for each drop height, with the individual repeat readings shown for 40 cm. Drop height (cm): 10, 20, 30, 40, 50 Repeat 1 (cm): 2.1, 2.9, 3.6, 4.2, 5.0 Repeat 2 (cm): 2.0, 2.8, 3.5, 4.5, 4.9 Repeat 3 (cm): 2.2, 3.0, 3.7, 4.4, 5.1 Mean diameter (cm): 2.1, 2.9, 3.6, ?, 5.0
(a)Identify the independent variable and the dependent variable in this investigation.(2)
(b)The student predicts that a greater drop height will produce a larger crater diameter. Suggest a reason for this prediction, in terms of energy.(1)
(c)Describe how the student could make this a fair test.(2)
(d)Calculate the mean crater diameter for a drop height of 40 cm, using the three repeat readings in the table.(2)
(e)Describe the pattern shown by the results in the table between drop height and mean crater diameter.(2)
(f)One of the readings for the 50 cm drop height (5.1 cm) is higher than the other two repeats. Suggest what the student should do with this reading, and why.(1)
10
An astronaut has a mass of 85 kg and is standing on the Earth's surface, where the gravitational field strength is 9.8 N/kg. Use the Physics Equations Sheet: weight = mass x gravitational field strength.
(3)
11
A space probe has a mass of 900 kg. The gravitational field strength on Earth's surface is 9.8 N/kg. The gravitational field strength on Mars's surface is 3.7 N/kg. Use the Physics Equations Sheet: weight = mass x gravitational field strength.
(a)Calculate the weight of the probe on Earth's surface.(2)
(b)Calculate the weight of the probe on Mars's surface.(2)
(c)The probe's mass is the same on Earth and on Mars, but its weight is not. Explain why.(1)
12
Geostationary satellites are used for television and communication signals.
(a)State two features of a geostationary satellite's orbit.(2)
(b)Explain why geostationary satellites are useful for TV and communication signals.(2)
13
Answer each of these short questions about space.
(a)What force keeps the planets in orbit around the Sun?(1)
(b)What is the name of the galaxy that contains our Solar System?(1)
(c)Which planet is known as the 'Red Planet'?(1)
(d)What is an artificial satellite?(1)
(e)What provides the energy released by the Sun?(1)
14
An astronaut has a mass of 70 kg. On Earth's surface her weight is 686 N. Use the Physics Equations Sheet: weight = mass x gravitational field strength.
(a)The gravitational field strength on the Moon is 1.6 N/kg. Calculate the astronaut's weight on the Moon.(2)
(b)State what her weight of 686 N on Earth tells you about her mass on the Moon, compared with her mass on Earth. Explain your reasoning.(2)
15
A satellite is in a circular geostationary orbit around the Earth, at a radius of 4.22 x 107 m, travelling at a speed of 3070 m/s. Use the Physics Equations Sheet: circumference = 2 x π x radius; speed = distance / time. Take π = 3.14.
(a)Calculate the circumference of the satellite's orbit.(2)
(b)Show that the time for one orbit is approximately 24 hours.(3)
16
The speed of light is 3 x 108 m/s. One year contains about 3.15 x 107 seconds. A light year is the distance that light travels in one year.
(a)State what is meant by a 'light year'.(1)
(b)Calculate the distance, in metres, that light travels in one year. Use the Physics Equations Sheet: distance = speed x time. Give your answer in standard form.(3)
(c)Explain why astronomers use light years, rather than kilometres, to describe distances to stars.(1)
17
Compare the life cycle of a star with a similar mass to the Sun with the life cycle of a star with a much greater mass than the Sun. Describe the key stages of each life cycle, and how each life cycle ends.
(6)
18
Light from most distant galaxies shows red-shift when observed from Earth.
(a)Explain what is meant by the red-shift of light from a distant galaxy.(2)
(b)Evaluate how observations of red-shift support the idea that the universe began with a Big Bang.(3)
19
The table shows the average distance from the Sun and the orbital period (time to orbit the Sun once) for the eight planets, measured in astronomical units (AU) and Earth years. Planet: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune Distance from Sun (AU): 0.39, 0.72, 1.00, 1.52, 5.20, 9.58, 19.2, 30.05 Orbital period (Earth years): 0.24, 0.62, 1.00, 1.88, 11.86, 29.4, 84.0, 164.8
(a)Describe the pattern shown by the data in the table between distance from the Sun and orbital period.(2)
(b)A dwarf planet orbits the Sun at an average distance of 40 AU. Using the pattern in the table, estimate its orbital period, and justify your estimate.(3)
20
Space agencies must decide whether to send unmanned (robotic) probes or manned (crewed) missions to explore space. Evaluate the advantages and disadvantages of using unmanned probes rather than manned missions to explore other planets.
(6)
21
A radio signal travels from Mars to Earth, a distance of 2.25 x 108 km, travelling at the speed of light, 3 x 108 m/s. Use the Physics Equations Sheet: speed = distance / time.
(a)Convert the distance from Mars to Earth into metres.(1)
(b)Calculate the time taken, in seconds, for the radio signal to travel from Mars to Earth.(2)
(c)Convert your answer to part b) into minutes.(1)
Mark scheme · K15 Space Physics
Question 1
B1 A cao
Answer: A
Question 2
(a) B1 a huge ball of hot gas that gives out its own light and heat, produced by nuclear fusion (oe)
(a) Answer: A huge ball of hot gas that produces its own light and heat by nuclear fusion.
(b) B1 a large, roughly spherical body that orbits a star and does not produce its own light (oe)
(b) Answer: A large, roughly spherical body that orbits a star and does not produce its own light.
(c) B1 an object that orbits a planet and was not made by humans, e.g. a moon (oe)
(c) Answer: An object that orbits a planet and was not made by humans, such as a moon.
Question 3
B1 (i) orbit
B1 (ii) gravity
B1 (iii) mass
B1 (iv) weaker
Answer: (i) orbit (ii) gravity (iii) mass (iv) weaker
Question 4
(a) B1 the Earth rotates (spins) on its axis, once approximately every 24 hours (oe)
(a) Answer: The Earth rotates on its axis once approximately every 24 hours.
(b) B1 the side facing the Sun is lit up (day), and the side facing away from the Sun is in darkness (night) (ft from part a)
(b) Answer: The side facing the Sun has day, and the side facing away from the Sun has night.
Question 5
(a) B1 about 23.5 degrees (accept 23 to 24 degrees)
(a) Answer: About 23.5 degrees.
(b) B1 in summer, the UK (Northern Hemisphere) is tilted towards the Sun, so sunlight is more concentrated and days are longer (oe)
(b) B1 in winter, the UK is tilted away from the Sun, so sunlight is more spread out and days are shorter, giving less energy overall (oe)
(b) Answer: In summer the UK is tilted towards the Sun, receiving more concentrated sunlight over longer days; in winter it is tilted away, receiving weaker, more spread-out sunlight over shorter days.
Question 6
(a) B1 lamp = Sun, globe = Earth (both needed)
(a) Answer: Lamp = Sun. Globe = Earth.
(b) B1 as the globe spins, the side facing the lamp is lit up, representing day (oe)
(b) B1 the side facing away from the lamp is in shadow, representing night, and this repeats as the globe keeps turning (oe, ft from part a)
(b) Answer: As the globe spins, the side facing the lamp is lit (day) and the side facing away is in shadow (night), repeating as the globe keeps turning.
(c) B1 any valid limitation, e.g. the model does not show the Earth's axial tilt, or the sizes and distances of the lamp and globe are not to the same scale as the Sun and Earth, or the globe does not also orbit the lamp (any one, oe)
(c) Answer: The model does not show the Earth's axial tilt (or the sizes/distances used are not to scale).
Question 7
(a) B1 new moon
(a) Answer: New moon.
(b) B1 full moon
(b) Answer: Full moon.
(c) B1 the Moon does not produce its own light; it only reflects light from the Sun (oe)
(c) B1 as the Moon orbits the Earth, we see different amounts of its sunlit half from Earth, which changes the phase we see (oe)
(c) Answer: The Moon only reflects sunlight, and as it orbits the Earth we see different amounts of its sunlit half, which changes the phase we see.
Question 8
(a) B1 the Moon must be directly between the Earth and the Sun (at the new moon position) (oe)
(a) B1 the Sun, Moon and Earth must be lined up closely enough that the Moon blocks sunlight from reaching part of the Earth's surface (oe)
(a) Answer: The Moon must be directly between the Earth and the Sun, with all three lined up closely enough for the Moon to block sunlight from part of the Earth.
(b) B1 the Moon's orbit is tilted at a small angle compared with the Earth's orbit around the Sun (oe)
(b) B1 so most months the Moon passes slightly above or below the direct Sun-Earth line, and only lines up exactly (causing an eclipse) occasionally (oe, ft from part a)
(b) Answer: The Moon's orbit is tilted slightly compared with the Earth's orbit around the Sun, so most months it passes above or below the direct Sun-Earth line, and only lines up exactly on occasional months.
Question 9
(a) B1 independent variable = the height the marble is dropped from
(a) B1 dependent variable = the diameter of the crater
(a) Answer: Independent variable: drop height. Dependent variable: crater diameter.
(b) B1 a greater drop height gives the marble more gravitational potential energy, so it has more kinetic energy (moves faster) just before impact, transferring more energy to the flour and making a bigger crater (oe)
(b) Answer: A greater drop height gives the marble more gravitational potential energy, so it hits the flour with more kinetic energy, transferring more energy and making a bigger crater.
(c) B1 use the same marble (same mass and size) for every drop (oe)
(c) B1 use the same depth and levelled surface of flour before each drop, and measure the crater diameter in the same way each time (oe)
(c) Answer: Use the same marble each time, and keep the flour at the same depth and level surface before every drop.
(e) B1 as drop height increases, the mean crater diameter increases (oe)
(e) B1 the increase in diameter for each extra 10 cm of drop height gets smaller (the graph would start to level off), oe, ft from part d
(e) Answer: As drop height increases, the mean crater diameter increases, but the size of the increase gets smaller at greater heights.
(f) B1 repeat that measurement again, or treat it as anomalous and exclude it from the mean calculation, because it does not agree closely with the other repeats, likely due to a measurement error (oe)
(f) Answer: Repeat the measurement (or exclude it from the mean), because it does not agree closely with the other two repeats, suggesting a measurement error.
Question 10
M1 correct substitution: weight = 85 x 9.8
A1 833 (N) cao
B1 correct unit, newtons (N), given with the answer
Answer: 833 N
Question 11
(a) M1 correct substitution: weight = 900 x 9.8
(a) A1 8820 N cao
(a) Answer: 8820 N
(b) M1 correct substitution: weight = 900 x 3.7
(b) A1 3330 N cao
(b) Answer: 3330 N
(c) B1 weight depends on the gravitational field strength of the planet as well as the mass, and Mars has a smaller gravitational field strength than Earth, so the same mass has a smaller weight on Mars (oe, ft from parts a and b)
(c) Answer: Weight depends on gravitational field strength as well as mass; Mars has a weaker gravitational field strength than Earth, so the same mass weighs less on Mars.
Question 12
(a) B1 it orbits directly above the equator (oe)
(a) B1 it has an orbital period of 24 hours, the same as the Earth's rotation, so it stays above the same point on the Earth's surface (oe)
(a) Answer: It orbits directly above the equator, with a 24 hour orbital period matching the Earth's rotation, so it stays above the same point on the surface.
(b) B1 the satellite always remains above the same point on the Earth (ft from part a) (oe)
(b) B1 so a receiving dish on the ground can be fixed in one direction, pointing permanently at the satellite, without needing to track its movement (oe)
(b) Answer: Because the satellite stays above the same point on Earth, a receiving dish can be fixed in one direction, pointing at the satellite, without needing to track it.
Question 13
(a) B1 gravity (gravitational force/attraction)
(a) Answer: Gravity.
(b) B1 the Milky Way
(b) Answer: The Milky Way.
(c) B1 Mars
(c) Answer: Mars.
(d) B1 a human-made object placed in orbit around a planet or moon (oe)
(d) Answer: A human-made object placed in orbit around a planet or moon.
(e) B1 nuclear fusion (of hydrogen nuclei into helium) (oe)
(e) Answer: Nuclear fusion, mainly of hydrogen into helium.
Question 14
(a) M1 correct substitution: weight = 70 x 1.6
(a) A1 112 N cao
(a) Answer: 112 N
(b) B1 her mass is the same on the Earth and on the Moon (ft)
(b) B1 because mass is the amount of matter in an object and does not depend on location; only her weight changes, because it depends on the gravitational field strength, which is different on the Moon (oe)
(b) Answer: Her mass is the same on the Earth and the Moon (70 kg), because mass does not depend on location; only her weight changes, since it depends on gravitational field strength.
Question 15
(a) M1 correct substitution: circumference = 2 x 3.14 x 4.22 x 107
(a) A1 awrt 2.65 x 108 m
(a) Answer: 2.65 x 108 m
(b) M1 correct substitution: time = 2.65 x 108 / 3070 (ft from part a)
(b) A1 awrt 8.6 x 104 s (86000 to 86400 s)
(b) A1 converts to hours (divides by 3600) to show approximately 24 hours cso
(b) Answer: Approximately 8.64 x 104 s, which is about 24 hours.
Question 16
(a) B1 the distance that light travels through space in one year (oe)
(a) Answer: The distance that light travels in one year.
(b) M1 correct substitution: distance = 3 x 108 x 3.15 x 107
(b) A1 9.45 x 1015 m cao
(b) B1 correct standard form, with unit metres
(b) Answer: 9.45 x 1015 m
(c) B1 distances to stars in kilometres would be extremely large numbers that are awkward to write and compare, so light years give a simpler, more manageable unit for these huge distances (oe)
(c) Answer: Distances to stars in kilometres would involve extremely large, awkward numbers, so light years give a simpler unit for such huge distances.
Question 17
Level 1 (1-2): Basic, mostly isolated statements about the life cycle of one type of star, with little or no comparison and limited use of scientific terms.
Level 2 (3-4): Some relevant, mostly correct stages given for both types of star, with a partial comparison between them; scientific terms used with reasonable accuracy.
Level 3 (5-6): A clear, correctly ordered and logically structured comparison of the life cycles of both types of star, explicitly comparing how each life cycle ends, using scientific terms accurately throughout.
Indicative content:
Both types of star begin as a nebula (a cloud of dust and gas) that contracts under gravity to form a protostar, and then a stable main sequence star, fusing hydrogen into helium.
A Sun-mass star spends most of its life as a stable main sequence star.
When hydrogen fuel starts to run low, a Sun-mass star expands into a red giant.
The red giant then loses its outer layers, leaving behind a small, dense white dwarf, which cools very slowly over a long time.
A much more massive star also forms a main sequence star, but burns fuel faster and has a shorter overall lifetime than a Sun-mass star.
A massive star expands into a red supergiant rather than a red giant.
The red supergiant's core collapses suddenly, causing a supernova explosion.
After the supernova, the remnant becomes a neutron star, or, for the most massive stars, a black hole, unlike the white dwarf left behind by a Sun-mass star.
Question 18
(a) B1 the wavelengths of light from the galaxy are shifted towards the red (longer wavelength) end of the spectrum, compared with light from a source that is not moving away (oe)
(a) B1 this happens because the galaxy is moving away from the Earth (oe)
(a) Answer: The wavelengths of light from the galaxy are shifted towards the red end of the spectrum, because the galaxy is moving away from Earth.
(b) B1 light from almost all distant galaxies shows red-shift, showing that nearly all galaxies are moving away from us (oe)
(b) B1 more distant galaxies generally show greater red-shift, showing that they are moving away faster, meaning the whole universe is expanding (oe, ft from part a)
(b) B1 if the universe is expanding now, it must have been smaller and denser in the past, which supports the idea that it began from an extremely small, dense point in a Big Bang (oe)
(b) Answer: Nearly all galaxies show red-shift (moving away), and more distant ones show greater red-shift (moving away faster), showing the universe is expanding; tracing this expansion backwards implies the universe was once much smaller and denser, supporting the Big Bang theory.
Question 19
(a) B1 as distance from the Sun increases, the orbital period also increases (oe)
(a) B1 the increase is not proportional; the orbital period increases much more quickly than the distance does (e.g. Neptune is about 77 times further out than Mercury, but its orbital period is about 690 times longer) (oe, accept any valid supporting comparison from the table)
(a) Answer: As distance from the Sun increases, orbital period increases, but much faster than in direct proportion.
(b) M1 identifies that 40 AU is a little further than Neptune's 30.05 AU (oe)
(b) A1 gives an estimate greater than Neptune's 164.8 years, e.g. in the range 190 to 260 years, with reasoning shown
(b) A1 justifies the estimate using the non-proportional trend identified in part a (period grows faster than distance), e.g. by extrapolating the increasing rate of growth, ft from part a
(b) Answer: Approximately 200 to 260 years (the true value, for the dwarf planet Pluto at 39.5 AU, is about 248 years); accept any reasoned estimate above 164.8 years that uses the trend from part a.
Question 20
Level 1 (1-2): Basic, mostly one-sided statements about unmanned or manned missions, with little or no comparison and limited use of scientific/technical terms.
Level 2 (3-4): Some relevant advantages and disadvantages of unmanned probes are given, with a partial comparison to manned missions; scientific/technical terms used with reasonable accuracy.
Level 3 (5-6): A clear, balanced and well-structured evaluation, weighing advantages against disadvantages, reaching a justified overall conclusion, using scientific/technical terms accurately throughout.
Indicative content:
Unmanned probes do not risk human life, so they can be sent on longer, more dangerous missions (e.g. to Mars or beyond) without endangering astronauts.
Unmanned probes do not need life-support systems (air, food, water, radiation shielding), so more of the mission's mass and cost can be spent on scientific instruments.
Unmanned probes are generally much cheaper to build and launch than crewed missions.
Unmanned probes can stay in space for much longer than a human crew could survive.
However, unmanned probes cannot make quick, flexible decisions or adapt to unexpected problems in the way a trained human crew could.
Human astronauts can carry out more complex tasks, repairs and hands-on sample collection than current robotic probes.
Manned missions tend to generate more public interest and inspiration, which can help secure funding for future space exploration.
A balanced conclusion should weigh reduced risk and cost against the flexibility and hands-on capability lost by not sending humans.
Question 21
(a) B1 2.25 x 1011 m cao
(a) Answer: 2.25 x 1011 m
(b) M1 correct substitution: time = 2.25 x 1011 / 3 x 108 (ft from part a)