CIE iGCSE Co-Ordinated Science P3.1 General properties of waves Exam Style Questions Paper 3
Question
(a) (i) Fig. 3.1 shows a skier standing on the snow.
When she stands on the snow without her skis, she sinks into the snow.
When she wears her skis, she can stand on the snow without sinking.
Explain these observations.
(ii) The skier makes a sound near a high wall.
The sound travels through the air as a wave.
The skier hears an echo.
State what happens to the sound wave at the high wall to cause an echo to be heard.
(b) Fig. 3.2 shows the forces acting on the skier on level snow when she is travelling in a snowmobile.
(i) State which force, J, K, L or M, is the weight of the snowmobile and skier.
(ii) State which force, J, K, L or M, is the friction force acting on the snowmobile.
(c) Fig. 3.3 shows the speed–time graph for the motion of the skier.
(i) State the maximum speed of the skier.
speed = …………………………………………. m / s
(ii) The skier is accelerating during the first 20 s of her journey.
Describe how the graph shows that the skier is accelerating.
(iii) Show that the distance travelled by the skier during the first 20 s is 50 m.
(d) The skier is exposed to ultraviolet radiation from the Sun.
Ultraviolet radiation is a form of ionising radiation.
Describe one danger to humans of being exposed to large quantities of ultraviolet radiation.
▶️Answer/Explanation
Ans : 3(a)(i) skis increase surface area ;
pressure is less with skis ; ORA
3(a)(ii) sound wave is reflected ;
3(b)(i) L ;
3(b)(ii) K ;
3(c)(i) 5 (m / s) ;
3(c)(ii) line has a slope / gradient ;
3(c)(iii) area under graph or ½ × 5 × 20 ;
3(d) skin cancer ;
Question
(a) The mass of the Sun is 1.97 × 1030 kg.
The average density of the Sun is 1410 kg / m3.
Calculate the volume of the Sun.
volume = ……………………………………………. m3
(b) The Sun is made of very hot gas.
(i) Suggest the main method of thermal energy transfer from the inside of the Sun to the surface of the Sun.
(ii) State the main method of energy transfer that occurs when infrared waves travel from
the Sun to the Earth through space.
(iii) Sound energy is produced by the Sun.
Explain why we are unable to hear this sound on Earth.
(c) (i) Fig. 12.1 shows an incomplete electromagnetic spectrum.
Write infrared radiation in its correct place.
(ii) State the electromagnetic radiation which has the highest frequency.
(iii) Explain why it takes the same time for infrared and visible light to travel from the Sun to
the Earth.
(d) Fig. 12.2 shows a sound wave.
(i) On Fig. 12.2, label the amplitude of the wave with a double-headed arrow (↔) or (↕) and the letter A.
(ii) On Fig. 12.2, label the wavelength of one wave with a double-headed arrow (↔) or (↕) and the letter W.
▶️Answer/Explanation
Ans : 12(a) volume = mass/density (in any form) or 1.97 × 1030 / 1410 ;
= 1.4 × 1027 (m3) ;
12(b)(i) convection ;
12(b)(ii) radiation ;
12(b)(iii) sound waves need a medium / cannot travel through a vacuum ;
12(c)(i) infrared to the right of visible light ;
12(c)(ii)gamma radiation ;
12(c)(iii) all electromagnetic waves / they travel at same speed ;
12(d)(i) amplitude correctly labelled ;
12(d)(ii) wavelength correctly labelled ;
Question
(a) An oil tanker is carrying petroleum.
Petroleum is a non-renewable energy source.
Identify the energy sources in Table 12.1 as renewable or non-renewable by placing a tick (3) for each one in the correct column.
One has been done for you.
(b) Fig. 12.1 shows a speed–time graph for the oil tanker.
The graph is divided into sections P, Q, R and S.
(i) State a section of the graph (P, Q, R or S) when the oil tanker is travelling at a constant speed and state this speed.
section ………………………………….
speed …………………………………. m / s
(ii) State the section of the graph (P, Q, R or S) when the oil tanker has the greatest acceleration.
Explain your answer.
section ………………………………….
explanation …………………………………………………………………………
(iii) Calculate the distance travelled by the oil tanker during section P.
distance = …………………………………………….. m
(c) The captain of the oil tanker uses a telescope to look at another ship.
The telescope uses a converging lens to focus the light and form an image of the other ship.
Fig. 12.2 shows two parallel light rays passing through a convex lens.
(i) Complete the light rays in Fig. 12.2 to show how the light rays are focused by the lens at point F.
(ii) State the name of point F.
(d) Fig. 12.3 shows a wave similar to a water wave on the surface of the sea.
(i) State which letter, A, B, C, D or E, is the amplitude of the wave.
letter ………………..
(ii) State which letter, A, B, C, D or E, is the wavelength of the wave.
letter ………………..
▶️Answer/Explanation
Ans : 12(a) 
2 or 3 correct ;
4 correct ;
12(b)(i) section Q and 1 (m / s) OR
section S and 5 (m / s) ;
12(b)(ii) section R AND
greatest gradient ;
12(b)(iii) area under graph or 1/2 × 1 × 300 ;
150 (m) ;
12(c)(i) both rays meet at F ;
12(c)(ii) principal focus ;
12(d)(i) B ;
12(d)(ii) E ;
Question
(a) Water vapour in the air over the sea comes from liquid water in the sea.
(i) State the name of the process by which liquid water in the sea forms water vapour in the air.
…………………………………………………………………………………………………………………….
(ii) Describe how the process named in (i) occurs. Use ideas about water molecules in your answer.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(b) Fig. 6.1 shows a boat moving at constant speed.
Four forces A, B, C and D act on the boat.
State the name of force C.
…………………………………………………………………………………………………………………….
(c) Fig. 6.2 shows a speed-time graph for the boat.
(i) Determine the speed of the boat.
speed = …………………………………………. m/s
(ii) Calculate the distance travelled by the boat in 200s.
distance = …………………………………………….. m
(d) Fig. 6.3 shows a wave similar to a water wave on the surface of the sea.
(i) Determine the wavelength of the wave.
wavelength = …………………………………………….. m
(ii) On Fig. 6.3, indicate with a double headed arrow (↕ or ↔) the amplitude of the wave.
(iii) The frequency of the wave is 0.08Hz.
Calculate how many wavefronts pass a fixed point in 25 seconds.
▶️Answer/Explanation
Ans: 6(a)(i) evaporation
6(a)(ii) fastest moving/most energetic molecules/particles ;
escape from surface ;
6(b) Weight ;
6(c)(i) 4.4 (m/s) ;
6(c)(ii) distance = speed × time (in any form symbols or words) or 4.4 × 200 or area under graph ;
880 (m) ;
6(d)(i) 8 (m) ;
6(d)(ii) amplitude correctly indicated ;
6(d)(iii) 2.0 ;
Question
Bats use the reflection of sound waves to determine the position of objects.
Fig. 6.1 shows a bat, and a moth flying in front of the bat.
(a) State the name given to a reflected sound wave. (Topic – P3.4)
▶️Answer/Explanation
Echo
Explanation: An echo is the reflection of sound waves off a surface, which is how bats detect objects in their environment.
(b) Some bats are able to detect ultraviolet radiation. Ultraviolet radiation is part of the electromagnetic spectrum. (Topic – P3.3)
(i) On the incomplete electromagnetic spectrum shown in Fig. 6.2, place ultraviolet in the correct position.
▶️Answer/Explanation
Ultraviolet should be placed between X-rays and infrared.
Explanation: The electromagnetic spectrum is ordered by wavelength and frequency. Ultraviolet (UV) radiation has a shorter wavelength and higher frequency than visible light but longer wavelength and lower frequency than X-rays.
(ii) State which part of the electromagnetic spectrum has the lowest frequency.
▶️Answer/Explanation
Radio waves
Explanation: Radio waves have the longest wavelength and the lowest frequency in the electromagnetic spectrum.
(c) A bat produces a sound wave with a frequency of 200 kHz and a wavelength of 0.0016 m.
(i) Draw straight lines to link each wave term to its definition. (Topic – P3.1)
▶️Answer/Explanation
Amplitude – Maximum displacement of points on a wave
Frequency – Number of waves passing a fixed point per second
Wavelength – Distance between the peaks on consecutive waves
Explanation: Amplitude is the height of the wave, frequency is how often the wave passes a point, and wavelength is the distance between two consecutive peaks or troughs.
(ii) Explain why a human cannot hear the sound emitted by the bat. (Topic – P3.4)
▶️Answer/Explanation
Humans cannot hear sounds with frequencies above 20 kHz.
Explanation: The human hearing range is typically between 20 Hz and 20 kHz. The bat’s sound wave has a frequency of 200 kHz, which is well above the upper limit of human hearing.
(iii) The bat changes the frequency of the sound it produces from 200 kHz to 250 kHz. State what happens to the pitch of the sound. (Topic – P3.4)
▶️Answer/Explanation
The pitch increases.
Explanation: Pitch is directly related to frequency. As the frequency increases from 200 kHz to 250 kHz, the pitch of the sound also increases.
Question(a)
An astronomer on Earth is able to see the Moon even though the Moon does not emit visible light.
State one property of visible light that enables observation of the Moon.
▶️Answer/Explanation
Answer: Reflection
Explanation: The Moon is visible from Earth because it reflects sunlight. Visible light from the Sun hits the Moon’s surface and is reflected back to Earth, allowing us to see the Moon even though it does not emit its own visible light.
Question(b)
Visible light is part of the electromagnetic spectrum.
Place visible light in the correct place in the incomplete electromagnetic spectrum in Fig. 3.1.
▶️Answer/Explanation
Answer: Visible light should be placed in the middle box between ultraviolet and infrared.
Explanation: The electromagnetic spectrum is arranged in order of increasing wavelength or decreasing frequency. Visible light falls between ultraviolet (shorter wavelength) and infrared (longer wavelength).
Question(c)(i)
Light rays from the Moon travel at \(3 \times 10^5 \, \text{km}/\text{s}\) to reach the astronomer on Earth.
The distance travelled is 400 000 km.
Calculate the time taken for the light rays to travel from the Moon to the Earth.
▶️Answer/Explanation
Answer: 1.33 s
Explanation: To calculate the time taken, we use the formula: \[ \text{time} = \frac{\text{distance}}{\text{speed}} \] Given: \[ \text{distance} = 400\,000 \, \text{km}, \quad \text{speed} = 3 \times 10^5 \, \text{km/s} \] Substituting the values: \[ \text{time} = \frac{400\,000}{3 \times 10^5} = 1.33 \, \text{s} \] Therefore, the time taken is 1.33 seconds.
Question(c)(ii)
Explain why sound waves are unable to travel from the Moon to the Earth.
▶️Answer/Explanation
Answer: Sound waves cannot travel through a vacuum.
Explanation: Sound waves require a medium (such as air, water, or solid materials) to travel through. Since space between the Moon and Earth is a vacuum (no medium), sound waves cannot propagate from the Moon to the Earth.
Question(d)(i)
The astronomer uses lenses in a telescope to look at the Moon.
Fig. 3.2 shows rays of light passing through a lens.
On Fig. 3.2, label the focal length of the lens with a double-headed arrow (←).
▶️Answer/Explanation
Answer: The focal length should be labeled with a double-headed arrow from the center of the lens to the focal point (F).
Explanation: The focal length is the distance between the center of the lens and the focal point (F), where parallel rays of light converge after passing through the lens.
Question(d)(ii)
On Fig. 3.2, label the principal focus of the lens with the letter F.
▶️Answer/Explanation
Answer: The principal focus should be labeled with the letter F at the focal point.
Explanation: The principal focus (F) is the point where parallel rays of light converge after passing through the lens. It is located along the principal axis of the lens.
Question(e)(i)
An astronaut on the Moon is exposed to ionising background radiation.
State one effect of ionising radiation on the human body.
▶️Answer/Explanation
Answer: Cancer or mutation
Explanation: Ionising radiation can damage the DNA in cells, leading to mutations or uncontrolled cell growth, which can result in cancer. It can also cause other harmful effects such as radiation sickness or genetic mutations.
Question(e)(ii)
Suggest one source of background radiation on the Moon.
▶️Answer/Explanation
Answer: Cosmic radiation
Explanation: The Moon has no atmosphere to protect it from cosmic radiation, which comes from outer space. This radiation is a significant source of background radiation on the Moon.
Question
(a) A school orchestra is practising.
Table 9.1 shows the highest and lowest sound frequencies of some of the musical instruments in the orchestra.
| Instrument | Highest Frequency (Hz) | Lowest Frequency (Hz) |
|---|---|---|
| Flute | 2600 | 260 |
| Guitar | 1200 | 70 |
| Piano | 4200 | 30 |
| Violin | 3500 | 200 |
(i) State what is meant by the frequency of a wave.
▶️Answer/Explanation
The frequency of a wave is the number of waves produced per second or the number of waves passing a fixed point per second.
(ii) State which instrument in Table 9.1 produces the sound with the lowest pitch.
▶️Answer/Explanation
The piano produces the sound with the lowest pitch because it has the lowest frequency (30 Hz).
(iii) State which instrument in Table 9.1 produces sound with the widest range of frequencies.
▶️Answer/Explanation
The piano produces sound with the widest range of frequencies, from 30 Hz to 4200 Hz.
(iv) State the normal audible frequency range for a healthy human ear.
▶️Answer/Explanation
The normal audible frequency range for a healthy human ear is from 20 Hz to 20,000 Hz.
(b) A flute is made from a nickel alloy. The volume of the alloy used to make the flute is 90 cm3. The mass of the flute is 801 g.
(i) Calculate the density of the alloy. State the unit of your answer.
▶️Answer/Explanation
Density = Mass / Volume = 801 g / 90 cm3 = 8.90 g/cm3.
(ii) Calculate the weight of the flute. The gravitational field strength \( g \) is 10 N/kg.
▶️Answer/Explanation
Weight = Mass × Gravitational field strength = 0.801 kg × 10 N/kg = 8.01 N.