Question

a man is standing 3om away from a large wall and call his friend and hear an echo .calculate after what time does he hear an echo? ( speed of the sound in air = 330m/s)

Answer 1

Hello mate,
The Distance between the Wall and the man=30m
Speed of sound=330m/s
So, we know that,
distance =speed *time
30m=330m/s*time
time=30m/330m/s
time=0.09seconds
So time taken to the echo come back to the man is 2t=2*0.9 seconds=1.8 seconds,
Therefore, The man hears the echo after 1.8 seconds..

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