Question

a boy stands 165 m in front of a high wall and then blows a whistle. calculate the time interval when he hears an echo ( let the speed of sound be 330 m/s)​

Answer 1

Explanation:

t be the time interval for hearing an echo, the sound travels distance in time t is S=2×85=170m.

Using formula, S=vt,  t=S/v=170/340=0.5s

Answer 2

Answer:

S =2×165 =330

s=vt,t=s/v

330/330 =1s