Question

An echo repeats two syllables. If the velocity of sound is 330 m/s, then the distance of the reflecting surface is(a) 66.0 m(b) 33.0 m(c) 99.0 m(d) 16.5 m

Answer 1

Given, speed of sound = 330 m/s

Now, the minimum time to hear an echo is 0.1s

So speed = 2distance/time

2distance = speed * time

distance = speed * time /2

distance = 330 * 0.1 /2

distance = 33 / 2

distance = 16.5 m

So, option d) 16.5 m is correct.