Physics (AS & A Level) · Oct / Nov 2017 · Paper 12 · Question 24

A vibrating tuning fork is held above a glass cylinder filled to the top with water. The water level is steadily lowered. A loud sound is first heard when the water level is 83.5 cm above the bench. The next loud sound is heard when the water level is 17.1 cm above the bench. The speed of sound in air is 340 m s⁻¹. What is the frequency of the tuning fork?

1. A128 Hz
2. B256 Hz
3. C384 Hz
4. D512 Hz

As printed in the paper