A tuning fork of frequency is moving towards a wall with a velocity of

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

Problem

A tuning fork of frequency

56\,\text{Hz}

is moving towards a wall with a velocity of

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

. If the speed of sound is

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

, then the number of beats heard per second by a stationary observer lying between the tuning fork and the wall is (1) 2 (2) 4 (3) zero (4) 8