Sound Wave Properties

00:00 6 marks

A student investigates the properties of a sound wave travelling through air. The frequency of the sound wave is 440 Hz. The speed of sound in air is 340 m s⁻¹.

(a) Define *wavelength*. [1]
(b) Calculate the wavelength of the sound wave. [1]
(c) The sound wave enters a region of warmer air where the speed of sound is higher. State and explain the effect, if any, on the frequency of the sound wave. [2]
(d) Describe the difference between a transverse wave and a longitudinal wave, using sound waves and light waves as examples. [2]

Part a

1 minutes 1 marks

Question

Define *wavelength*. [1]

Hint Hint

Hint

Think about the distance between repeating points on a wave, like two consecutive crests, or the distance the wave covers in one full cycle.

Answer Answer
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Explanation Explanation

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Complete Answer

The minimum distance between two points on a wave oscillating in phase / distance covered by one complete oscillation.

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Part b

1 minutes 1 marks

Question

Calculate the wavelength of the sound wave. [1]

Hint Hint

Hint

Use the fundamental wave equation that relates wave speed, frequency, and wavelength.

Answer Answer
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Explanation Explanation

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Complete Answer

0.77 m

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Part c

2 minutes 2 marks

Question

The sound wave enters a region of warmer air where the speed of sound is higher. State and explain the effect, if any, on the frequency of the sound wave. [2]

Hint Hint

Hint

Think about what determines the frequency of a wave. Is it the source or the medium? How does this relate to what happens at a boundary?

Answer Answer
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Complete Answer

Frequency remains unchanged because it is determined by the source of the wave and does not change when the wave enters a different medium.

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Part d

2 minutes 2 marks

Question

Describe the difference between a transverse wave and a longitudinal wave, using sound waves and light waves as examples. [2]

Hint Hint

Hint

Focus on the direction of the oscillations (of particles or fields) relative to the direction the wave travels (energy propagation). Provide the correct example for each type.

Answer Answer
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Explanation Explanation

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Complete Answer

Transverse: Oscillation perpendicular to energy transfer (e.g., Light waves). Longitudinal: Oscillation parallel to energy transfer (e.g., Sound waves).

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