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13+ · Physics

CE.S-P3 Physics: Light, Sound and Space

ISEB CE ISEB CE 13+ Science (Physics) · Calculator allowed · about 85 minutes

Total Marks

Name: _______________________________ Date: ____ / ____ / ______

Answer ALL questions. Show all your working.

Priya is investigating how well light passes through different materials: a sheet of clear glass, a piece of greaseproof (tracing) paper, and a wooden door.

(a)State whether clear glass is transparent, translucent or opaque.(1)

(b)State whether greaseproof paper is transparent, translucent or opaque.(1)

(c)State whether the wooden door is transparent, translucent or opaque.(1)

(d)A lamp is placed behind the wooden door. State what you would expect to see on the floor in front of the door, and explain why.(1)

(Total for Question 1 is 4 marks)

Tom is learning about how sound is made and how it travels.

(a)State what all sources of sound have in common.(1)

(b)Tom plucks a guitar string and then rings a bell. State the part of the guitar that vibrates to produce sound, and the part of the bell that vibrates to produce sound.(2)

(c)Astronauts on a spacewalk outside the International Space Station cannot hear each other speak directly, even when close together, and must use radios instead. State why sound cannot travel through the vacuum of space.(1)

(Total for Question 2 is 4 marks)

The solar system is made up of the Sun, the planets, and other objects that orbit it.

(a)State the name of the star at the centre of the solar system.(1)

(b)State which planet in the solar system we live on.(1)

(c)State what is meant by a 'moon', using the Moon that orbits the Earth as your example.(1)

(d)Name the two planets that orbit closer to the Sun than the Earth does.(1)

(Total for Question 3 is 4 marks)

The Earth is constantly moving in space in two different ways: spinning on its own axis, and travelling around the Sun.

(a)State what causes day and night on Earth.(1)

(b)State how long the Earth takes to complete one full rotation on its axis.(1)

(c)State how long the Earth takes to complete one full orbit of the Sun.(1)

(d)State the shape of the Earth's orbit path around the Sun.(1)

(Total for Question 4 is 4 marks)

A ray of light hits a flat (plane) mirror.

(a)State the law of reflection.(1)

(b)The ray hits the mirror so that the angle between the incident ray and the mirror surface itself (not the normal) is 55 degrees. Calculate the angle of incidence, measured from the normal.(2)

(c)State the angle of reflection.(1)

(Total for Question 5 is 4 marks)

Amara puts a straw at an angle into a glass of water and looks at it from the side. The straw appears to bend at the point where it enters the water.

(a)Name this effect.(1)

(b)State what happens to the speed of light as it passes from air into water.(1)

(c)Explain why the straw appears to bend at the surface of the water.(2)

(Total for Question 6 is 4 marks)

White light is made up of a mixture of colours. When white light hits a coloured, opaque object, some colours are absorbed and some are reflected.

(a)State the three primary colours of light.(1)

(b)A red apple is seen in white light. Explain, in terms of absorption and reflection, why the apple looks red.(2)

(c)The same red apple is now placed under a blue light (containing no red light). State and explain what colour the apple will appear.(2)

(Total for Question 7 is 5 marks)

Match each part of the eye below to its correct function.

(a)State the function of the cornea and lens.(1)

(b)State the function of the retina.(1)

(c)State the function of the pupil.(1)

(d)State what happens to the size of the pupil in dim light, and explain why.(1)

(Total for Question 8 is 4 marks)

The human ear can detect a certain range of sound frequencies.

(a)State the approximate range of frequencies that a healthy human ear can hear.(1)

(b)Sound above the upper limit of human hearing is called ultrasound. State one animal that can hear ultrasound that humans cannot.(1)

(c)Bats use ultrasound to find their way around in the dark and to locate insects to eat. Describe, in simple terms, how a bat uses ultrasound to find the position of an object.(2)

(Total for Question 9 is 4 marks)

Jamal plucks a guitar string and investigates how changing the string affects the sound produced.

(a)State how the pitch of a sound is related to the frequency of the sound wave.(1)

(b)State how the loudness (volume) of a sound is related to the amplitude of the sound wave.(1)

(c)Jamal shortens the length of the vibrating part of the string (by pressing down on a fret), without changing how hard he plucks it. State and explain what happens to the pitch of the note produced.(2)

(Total for Question 10 is 4 marks)

During a thunderstorm, Chloe sees a flash of lightning and then hears the thunder 9 seconds later. The speed of sound in air is 340 m/s. The speed of light is so great that the time for light to reach Chloe can be taken as zero.

(a)Explain why Chloe sees the lightning before she hears the thunder, even though they happen at the same time.(1)

(b)Calculate the distance between Chloe and the place where the lightning struck.(2)

(c)State this distance in kilometres, to 1 decimal place.(1)

(Total for Question 11 is 4 marks)

Oliver stands facing a tall cliff and claps his hands once. He hears the echo of the clap 2.4 seconds later. The speed of sound in air is 340 m/s.

(a)Calculate the total distance travelled by the sound of the clap (there and back).(2)

(b)Calculate the distance between Oliver and the cliff.(2)

(c)Oliver measures the time using a stopwatch that he starts and stops by hand. Suggest one reason why this method might give an inaccurate value for the distance to the cliff.(1)

(Total for Question 12 is 5 marks)

The speed of a wave is linked to its frequency and wavelength by the equation: wave speed = frequency x wavelength.

(a)A sound wave in air has a frequency of 170 Hz and a wavelength of 2.0 m. Calculate the speed of this sound wave.(2)

(b)State what this value of 340 m/s represents.(1)

(Total for Question 13 is 3 marks)

The Moon does not produce its own light. We see it because it reflects sunlight, and its appearance from Earth changes throughout the month.

(a)State where the Moon gets the light that we see it by.(1)

(b)Explain why we see different phases of the Moon (e.g. new moon, half moon, full moon) during the month.(2)

(c)State the approximate length of time it takes for the Moon to complete one full cycle of phases (e.g. from one full moon to the next).(1)

(Total for Question 14 is 4 marks)

In a scale model of the solar system, the real distance from the Sun to the Earth (150 000 000 km) is represented by a distance of 15 cm in the model. The real distance from the Sun to Mars is 228 000 000 km.

(a)Calculate the scale used in the model, giving your answer in the form '1 cm represents ... km'.(2)

(b)Use your scale from part (a) to calculate the distance from the Sun to Mars in the same scale model.(2)

(Total for Question 15 is 4 marks)

The table below shows the approximate speed of sound in three different media.
Medium: air, water, steel
Speed of sound (m/s): 340, 1500, 5000

(a)State, using the table, which of the three media sound travels fastest through.(1)

(b)A sound wave travels a distance of 1000 m through steel. Calculate the time this takes.(2)

(c)Calculate the time the same sound wave would take to travel the same 1000 m distance through air.(2)

(d)Explain, in terms of particles, why sound travels faster through steel (a solid) than through air (a gas).(1)

(Total for Question 16 is 6 marks)

A teacher demonstrates that sound cannot travel through a vacuum. She places an electric bell inside a sealed glass jar connected to a vacuum pump. With air in the jar, the bell can be clearly heard ringing. She then uses the pump to remove the air from the jar, while the bell keeps ringing inside.

(a)State what happens to the loudness of the bell as the air is gradually removed from the jar.(1)

(b)Identify the independent variable in this demonstration.(1)

(c)Identify the dependent variable in this demonstration.(1)

(d)State one variable that should be kept the same (controlled) for this to be a fair test.(1)

(e)Explain what this demonstration shows about how sound travels.(2)

(Total for Question 17 is 6 marks)

Light travels through space at a speed of 300 000 km/s. The average distance from the Sun to the Earth is 150 000 000 km. The average distance from the Earth to the Moon is 384 000 km.

(a)Calculate the time it takes for light to travel from the Sun to the Earth, giving your answer in seconds.(2)

(b)Convert your answer to part (a) into minutes and seconds.(1)

(c)Calculate the time it takes for light to travel from the Earth to the Moon, giving your answer to 2 significant figures.(2)

(d)State one reason why astronauts communicating by radio between the Earth and the Moon notice a short delay in their conversation, using your answer to part (c).(1)

(Total for Question 18 is 6 marks)

A solar eclipse and a lunar eclipse both involve the Sun, Earth and Moon lining up, but in a different order each time.

(a)State the order of the Sun, Earth and Moon during a solar eclipse.(1)

(b)State the order of the Sun, Earth and Moon during a lunar eclipse.(1)

(c)Explain what happens during a solar eclipse.(2)

(d)The Moon orbits the Earth roughly every month, yet eclipses do not happen every month. Explain why.(2)

(Total for Question 19 is 6 marks)

Using ideas about the Earth's rotation on its axis, its orbit around the Sun, and the tilt of its axis, explain: why we experience day and night, why a year has a fixed length, and why the United Kingdom has warmer weather in summer than in winter.

(Total for Question 20 is 6 marks)

Mark scheme · CE.S-P3 Physics: Light, Sound and Space

Question 1

(a) B1 transparent
(a) Answer: Transparent
(b) B1 translucent
(b) Answer: Translucent
(c) B1 opaque
(c) Answer: Opaque
(d) B1 a dark shadow, because the wood is opaque and blocks (absorbs/reflects) all the light, so no light passes through it to reach the floor beyond, oe
(d) Answer: A dark shadow, because the opaque wood blocks all the light from the lamp.

Question 2

(a) B1 they are all vibrating (oscillating), oe
(a) Answer: They are all vibrating.
(b) B1 the guitar string itself vibrates
(b) B1 the (metal) body/rim of the bell vibrates
(b) Answer: The guitar string vibrates; the metal body of the bell vibrates.
(c) B1 sound needs a medium (particles) to travel through, because it travels as vibrations passed between particles; a vacuum has no particles, so sound cannot travel through it, oe
(c) Answer: Sound needs a medium (particles) to travel through, and there are no particles in a vacuum.

Question 3

(a) B1 the Sun
(a) Answer: The Sun
(b) B1 Earth
(b) Answer: Earth
(c) B1 a moon is a natural object that orbits a planet; the Moon is Earth's only natural satellite and orbits the Earth, oe
(c) Answer: A moon is a natural object that orbits a planet; the Moon orbits the Earth.
(d) B1 Mercury and Venus, both needed, any order
(d) Answer: Mercury and Venus

Question 4

(a) B1 the spin (rotation) of the Earth on its own axis, oe
(a) Answer: The rotation of the Earth on its own axis.
(b) B1 24 hours (1 day)
(b) Answer: 24 hours
(c) B1 1 year (about 365 days / 365.25 days), oe
(c) Answer: 1 year (about 365 days)
(d) B1 an ellipse (a slightly squashed circle), oe; accept 'roughly circular'
(d) Answer: An ellipse (a slightly squashed/oval circle).

Question 5

(a) B1 the angle of incidence equals the angle of reflection, oe
(a) Answer: The angle of incidence equals the angle of reflection.
(b) M1 recognises the normal is at 90 degrees to the mirror surface, so angle of incidence = 90 - 55
(b) A1 35 degrees, cao
(b) Answer: 35 degrees
(c) B1 35 degrees, ft from (b)
(c) Answer: 35 degrees

Question 6

(a) B1 refraction
(a) Answer: Refraction
(b) B1 it slows down (decreases), oe
(b) Answer: It slows down.
(c) B1 light travels more slowly in water than in air (water is optically denser), oe
(c) B1 because the light rays change speed as they cross the boundary at an angle, they change direction (bend towards the normal) as they enter the water, making the straw look bent/displaced, oe
(c) Answer: Light slows down and bends towards the normal as it enters the water at an angle, so the part of the straw under water appears displaced, making it look bent.

Question 7

(a) B1 red, green and blue, all three needed
(a) Answer: Red, green and blue
(b) B1 the apple's surface reflects red light
(b) B1 and absorbs all the other colours in the white light (e.g. green and blue), oe
(b) Answer: The apple reflects red light and absorbs all the other colours in the white light, so only red light reaches the eye.
(c) B1 black
(c) B1 because the apple can only reflect red light, but there is no red light in the blue light shining on it, so it reflects no light and looks black, oe
(c) Answer: Black, because the apple can only reflect red light, and there is no red light present in the blue light to reflect.

Question 8

(a) B1 they refract (bend) light rays to focus an image (onto the retina), oe
(a) Answer: They refract (bend) light rays to focus an image onto the retina.
(b) B1 it detects light (contains light-sensitive cells) and sends signals to the brain via the optic nerve, oe
(b) Answer: It detects light and sends signals to the brain via the optic nerve.
(c) B1 it is the hole/gap that lets light into the eye, oe
(c) Answer: It is the hole that lets light into the eye.
(d) B1 the pupil gets bigger (dilates), to let more light into the eye so the person can still see, oe
(d) Answer: The pupil gets bigger, to let more light into the eye.

Question 9

(a) B1 about 20 Hz to 20 000 Hz (20 kHz), oe
(a) Answer: About 20 Hz to 20 000 Hz
(b) B1 any one of: dog, bat, dolphin, cat, mouse (or other suitable animal)
(b) Answer: For example, a dog or a bat.
(c) B1 the bat sends out (emits) a pulse of ultrasound, oe
(c) B1 the ultrasound reflects off the object and returns to the bat as an echo; the bat uses the time this takes (and the direction of the echo) to work out the object's distance and position, oe
(c) Answer: The bat emits a pulse of ultrasound, which reflects off the object and returns as an echo; the bat uses the time taken for the echo to return to work out the object's distance and position.

Question 10

(a) B1 the higher the frequency, the higher the pitch, oe
(a) Answer: The higher the frequency, the higher the pitch.
(b) B1 the greater the amplitude, the louder the sound, oe
(b) Answer: The greater the amplitude, the louder the sound.
(c) B1 the pitch increases (gets higher), oe
(c) B1 because a shorter length of string vibrates at a higher frequency, oe
(c) Answer: The pitch gets higher, because a shorter string vibrates at a higher frequency.

Question 11

(a) B1 light travels enormously faster than sound, so it reaches Chloe almost instantly, while the sound takes a measurable time to arrive, oe
(a) Answer: Light travels much faster than sound, so it arrives almost instantly while the sound takes a noticeable time to travel to her.
(b) M1 distance = speed x time = 340 x 9
(b) A1 3060 m, cao
(b) Answer: 3060 m
(c) B1 3.1 km, ft from (b)
(c) Answer: 3.1 km

Question 12

(a) M1 distance = speed x time = 340 x 2.4
(a) A1 816 m, cao
(a) Answer: 816 m
(b) M1 divide the total distance by 2 (their (a) / 2)
(b) A1 408 m, cao, ft from (a)
(b) Answer: 408 m
(c) B1 any sensible reason, e.g. his own reaction time when starting/stopping the stopwatch introduces an error into the measured time, oe
(c) Answer: His reaction time when starting and stopping the stopwatch by hand introduces an error into the measured time.

Question 13

(a) M1 v = f x wavelength = 170 x 2.0
(a) A1 340 m/s, cao
(a) Answer: 340 m/s
(b) B1 this is the (typical/accepted) speed of sound in air, oe, ft from (a)
(b) Answer: This is the typical speed of sound in air.

Question 14

(a) B1 it reflects light from the Sun; the Moon does not produce its own light, oe
(a) Answer: The Moon reflects light from the Sun.
(b) B1 as the Moon orbits the Earth, the relative positions of the Sun, Earth and Moon change, oe
(b) B1 so different amounts of the Moon's sunlit half are visible from Earth at different times, oe
(b) Answer: As the Moon orbits the Earth, the relative positions of the Sun, Earth and Moon change, so we see different amounts of the Moon's sunlit half at different times.
(c) B1 about 4 weeks (about 28-30 days, roughly one month), oe
(c) Answer: About 4 weeks (roughly one month).

Question 15

(a) M1 scale = 150 000 000 / 15
(a) A1 1 cm represents 10 000 000 km, cao
(a) Answer: 1 cm represents 10 000 000 km
(b) M1 228 000 000 / their scale from (a), or 228/150 x 15
(b) A1 22.8 cm, cao, ft from (a)
(b) Answer: 22.8 cm

Question 16

(a) B1 steel
(a) Answer: Steel
(b) M1 time = distance / speed = 1000 / 5000
(b) A1 0.2 s, cao
(b) Answer: 0.2 s
(c) M1 time = 1000 / 340
(c) A1 2.9 s, allow awrt 2.9
(c) Answer: 2.9 s (2 s.f.)
(d) B1 in a solid the particles are much closer together (and more strongly bonded) than in a gas, so vibrations (energy) are passed from particle to particle more quickly, oe
(d) Answer: In a solid the particles are much closer together than in a gas, so vibrations pass from particle to particle more quickly.

Question 17

(a) B1 the bell sounds gradually quieter, until it cannot be heard at all once (almost) all the air has been removed, oe
(a) Answer: It gets gradually quieter until it can no longer be heard.
(b) B1 the amount of air (pressure) inside the jar, oe
(b) Answer: The amount of air (pressure) inside the jar.
(c) B1 the loudness of the bell heard by the observer, oe
(c) Answer: The loudness of the bell heard by the observer.
(d) B1 any one sensible control variable, e.g. how the bell is struck/powered, the distance and position of the observer from the jar, or the volume setting of the bell
(d) Answer: For example, the position of the observer relative to the jar should stay the same.
(e) B1 sound needs a medium (a substance made of particles) to travel through, oe
(e) B1 because in a vacuum there are (almost) no particles to vibrate and pass on the sound energy, so sound cannot travel through empty space, oe
(e) Answer: Sound needs a medium to travel through; with (almost) no particles left in the vacuum to vibrate and pass on the energy, the sound cannot travel through empty space, so it fades away.

Question 18

(a) M1 time = distance / speed = 150 000 000 / 300 000
(a) A1 500 s, cao
(a) Answer: 500 s
(b) B1 8 minutes 20 seconds, ft from (a)
(b) Answer: 8 minutes 20 seconds
(c) M1 time = 384 000 / 300 000
(c) A1 1.3 s, allow awrt 1.3
(c) Answer: 1.3 s (2 s.f.)
(d) B1 radio waves travel at the speed of light, so there is a real delay of about 1.3 seconds for a signal to travel each way (about 2.6 seconds there and back), ft from (c)
(d) Answer: Radio signals travel at the speed of light, so each one-way message takes about 1.3 seconds to arrive, causing a noticeable delay in conversation.

Question 19

(a) B1 Sun, Moon, Earth, oe (the Moon is directly between the Sun and the Earth)
(a) Answer: Sun, Moon, Earth (the Moon is directly between the Sun and the Earth).
(b) B1 Sun, Earth, Moon, oe (the Earth is directly between the Sun and the Moon)
(b) Answer: Sun, Earth, Moon (the Earth is directly between the Sun and the Moon).
(c) B1 the Moon passes directly between the Sun and the Earth, oe
(c) B1 so the Moon blocks (some or all of) the Sun's light from reaching a small part of the Earth, casting a shadow there, oe
(c) Answer: The Moon passes directly between the Sun and the Earth, blocking some or all of the Sun's light from reaching a small part of the Earth and casting a shadow there.
(d) B1 the Moon's orbit is tilted slightly compared with the Earth's orbit around the Sun, oe
(d) B1 so, most months, the Sun, Earth and Moon do not line up exactly (the Moon passes above or below the direct line), and an eclipse only happens when the alignment is close enough, oe
(d) Answer: The Moon's orbit is tilted slightly compared with the Earth's orbit around the Sun, so most months the three bodies do not line up exactly, and an eclipse only occurs when the alignment is close enough.

Question 20

Level 1 (1-2): Basic, isolated statement(s), such as 'the Earth spins' or 'the Earth goes round the Sun', with little or no explanation of how this causes day/night, the length of a year, or the seasons.
Level 2 (3-4): A generally correct explanation of day and night (linked to the Earth's rotation) and of the length of a year (linked to the Earth's orbit), but the explanation of the seasons is incomplete, only partly correct, or missing a clear link to the axial tilt.
Level 3 (5-6): A clear, logically linked explanation covering all three ideas: day and night caused by the Earth's rotation on its axis (about once every 24 hours), the fixed length of a year caused by the time taken for one full orbit of the Sun (about 365 days), and the seasons caused by the tilt of the Earth's axis (about 23.5 degrees), correctly explaining that this tilt means the UK is tilted towards the Sun in summer and away from the Sun in winter.
Indicative content:
- The Earth spins (rotates) on its own axis once approximately every 24 hours; the side facing the Sun experiences day, and the side facing away experiences night.
- The Earth orbits (travels around) the Sun once approximately every 365 days (365.25 days); this fixed orbit time is what defines the length of one year.
- The Earth's axis is tilted at an angle of about 23.5 degrees to its orbit, and this tilt stays pointing in the same direction in space as the Earth orbits the Sun.
- During the UK's summer, the northern hemisphere (including the UK) is tilted towards the Sun; this gives more direct/concentrated sunlight (the Sun is higher in the sky) and longer daylight hours, so it feels warmer.
- During the UK's winter, the northern hemisphere is tilted away from the Sun; sunlight is more spread out (the Sun is lower in the sky) and daylight hours are shorter, so it feels colder.
- The seasons are caused by this changing tilt relative to the Sun as the Earth orbits, not by the Earth being closer to or further from the Sun during its orbit.

Physics: Light, Sound and Space - Worksheets, Questions and Revision