Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Waves
356 practice questions
Topics covered
Practice questions
91–100 of 181 · Normal
Question 91
2 marks · Normal
Answer and see the solution →Describe what happens to the wavelength and frequency of sound waves ahead of a car as it moves towards a stationary observer.
Question 92
3 marks · Normal
Answer and see the solution →A train travels towards a platform at high speed.
(a)[2 marks]Explain how the frequency of the sound heard by a person standing on the platform compares to the frequency emitted by the train.
(b)[1 mark]If the train then stops, what happens to the sound's frequency for the person on the platform?
Question 93
4 marks · Normal
Answer and see the solution →A police car moves directly towards a stationary observer at a speed of 30 m/s. The siren emits a sound with a frequency of 800 Hz. The speed of sound in air is 340 m/s.
(a)[1 mark]Explain why the observer hears a higher frequency as the car approaches.
(b)[3 marks]Calculate the observed frequency of the siren heard by the observer. Give your answer to 2 significant figures.
Question 94
3 marks · Normal
Answer and see the solution →A graph below shows how the frequency of a sound heard by an observer changes as a vehicle passes by:
(a)[1 mark]Describe the main feature shown on the graph.
(b)[2 marks]Explain, using the Doppler effect, why the frequency drops suddenly at around t = 5 s.
Question 95
3 marks · Normal
Answer and see the solution →A football referee blows the whistle while jogging towards some players. The players report hearing a whistle that is slightly higher in pitch than normal.
Explain, using the idea of wavefronts, why the frequency of sound is heard as higher.
Question 96
2 marks · Normal
Answer and see the solution →Give one everyday example of the Doppler effect with sound, and briefly explain how it is noticed.
Question 97
3 marks · Normal
Answer and see the solution →Describe a practical experiment you could carry out to demonstrate the Doppler effect using sound.
Question 98
5 marks · Normal
Answer and see the solution →A ripple tank is used to study water waves. When the frequency of the motor is increased, the spacing of the wavefronts changes.
(a)[2 marks]Describe, using the terms wavelength and frequency, how the spacing between wavefronts changes as the frequency is increased.
(b)[3 marks]The distance from a crest to the next crest in the tank is measured to be . The frequency of vibration is . Calculate the speed of the water waves. Give your answer in .
Question 99
4 marks · Normal
Answer and see the solution →A percussionist strikes a drum repeatedly at a constant rate, producing sound waves.
(a)[2 marks]State whether sound waves in air are longitudinal or transverse and explain your answer.
(b)[2 marks]The time between drum beats is . Calculate the frequency of the sound waves produced by the drum.
Question 100
5 marks · Normal
Answer and see the solution →The diagram shows a ray of light entering a glass block from air at an angle.
Refraction of a light ray entering glass The angle between the incident ray and the normal is 35°.
(a)[2 marks]Name the phenomenon shown by the light ray at the air-glass boundary and explain what causes it to occur.
(b)[2 marks]Describe what happens to the speed and direction of the light ray as it enters the glass.
(c)[1 mark]Draw and label on the diagram: - the angle of incidence - the angle of refraction.