Two identical tuning forks

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

Two identical tuning forks, each of frequency

340\,\text{Hz}

, are struck near a listener. One fork is then moved directly towards the listener with a constant speed

u

while the other remains stationary. If the listener hears

4

beats per second, calculate

u

. (Speed of sound in air

=340\,\text{m\,s}^{-1}

.) (a)

2.0\,\text{m\,s}^{-1}

(b)

4.0\,\text{m\,s}^{-1}

(c)

3.8\,\text{m\,s}^{-1}

(d)

8.0\,\text{m\,s}^{-1}