AQA GCSE Physics (8463), Higher tier · Waves › Waves in air, fluids and solids
Practise Sound waves. 12 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Humans can hear sound over a limited range of frequencies. Give the range of normal human hearing.
20 Hz to 20 kHz
Explain why a human cannot hear a sound with a frequency of 30 kHz.
30 kHz is above 20 kHz; the parts of the ear cannot vibrate at such a high frequency.
Write down the equation that links frequency, wavelength and wave speed.
wave speed = frequency × wavelength
A sound gets higher in pitch but stays the same loudness. Describe what happens to the frequency and to the amplitude of the sound wave.
Frequency increases; amplitude is unchanged.
Two students sit at opposite ends of a long wooden table in a quiet room. One student taps the table gently. The other student, with an ear pressed against the table, can hear the tap clearly, even though it cannot be heard through the air from that distance. State what this shows about sound and solids.
Sound can travel through solids.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Humans can hear sound over a limited range of frequencies.
(a) Give the range of normal human hearing.[2]
(b) Which of these sounds could not be heard by a human? Tick (✓) one box.[1]
A bat call at 45 kHz
A drum beat at 60 Hz
A whistle at 3 kHz
A bird song at 8 kHz
(c) When a sound wave reaches the ear, it makes a thin membrane in the ear vibrate. Name this membrane.[1]
(d) What type of wave is a sound wave in air? Tick (✓) one box.[1]
Electromagnetic
Longitudinal
Transverse
Show the answer and mark scheme
(a)Answer: 20 Hz to 20 kHz
(lowest) 20 Hz
(highest) 20 kHz / 20 000 Hz
(b)Answer: A bat call at 45 kHz
(c)Answer: The ear drum
ear drum
(d)Answer: Longitudinal
Question 2Medium8 marks
Kofi puts one ear against the end of a long steel railing. Priya stands at the other end of the railing, 170 m away, and hits the railing once with a hammer. Kofi hears two separate sounds. speed of sound in steel = 5100 m/s speed of sound in air = 340 m/s
(a) Explain why Kofi hears two sounds.[2]
(b) Calculate the time between the two sounds arriving.[4]
(c) Describe how the sound wave travels through the steel railing.[2]
Show the answer and mark scheme
(a)Answer: Sound reaches Kofi through the steel and through the air; it travels faster in steel so arrives at two different times.
one sound travels through the steel (railing) and the other travels through the air
sound travels faster in steel than in air, so the sound through the steel arrives first
(b)Answer: 0.47 s
time through air = 170 ÷ 340 = 0.50 (s)
time through steel = 170 ÷ 5100 = 0.033 (s)
difference = 0.50 − 0.033
0.47 (s)
(c)Answer: The particles of steel vibrate and pass the vibrations on to neighbouring particles.
the particles / atoms in the steel vibrate / oscillate (backwards and forwards)
the vibrations are passed on from particle to particle along the railing
Question 3Hard6 marks
Sound waves are pressure variations in the air. Parts of the human ear convert these pressure variations into vibrations of solid structures.
(a) Describe how a sound wave produces the sensation of sound.[2]
(b) Explain why a human cannot hear a sound with a frequency of 30 kHz.[2]
(c) A cat can hear sounds with frequencies up to about 64 kHz. Suggest why a cat's ear can respond to higher frequencies than a human ear.[1]
(d) Sound waves can also make solid objects vibrate outside the body. Give one example of a device in which sound waves make a solid part vibrate.[1]
Show the answer and mark scheme
(a)Answer: The pressure variations make the ear drum vibrate; the vibrations pass to other parts of the ear, which causes the sensation of sound.
the pressure variations (of the sound wave) make the ear drum vibrate
the vibrations are passed on to other (solid) parts of the ear, which causes the sensation of sound
(b)Answer: 30 kHz is above 20 kHz; the parts of the ear cannot vibrate at such a high frequency.
30 kHz is above the upper limit of human hearing (20 kHz)
the ear drum and other parts of the ear cannot vibrate at such a high frequency / the conversion of sound into vibrations of solids only works over a limited range of frequencies
(c)Answer: The vibrating parts of a cat's ear are smaller and lighter, so they can vibrate at higher frequencies.
the vibrating parts of a cat's ear (ear drum / small bones) are smaller / thinner / lighter, so they can vibrate at higher frequencies