Question

A boy claps his hands at the echo point on a hot summer day and distance between the two peaks is 34.2 m will he hear an echo

Answer 1

Answer:

The boy will hear the echo.

Condition for hearing the echo

Human ear cannot differntiate between the source and its echo, if the time gap between the two is less than 1/10 of a second.

Speed of the sound in air Vs = 343 m/s

Wehn the two peaks are 34.2 m apart, the distance traveled by the sound will be

Ds = 34.2 x 2 = 68.4 m

Thus total time taken for the clap sound to reach the boy after the claps,

T = Distance / Velocity of sound

T = 68.4 / 343

T = 0.199 s

∵ The time taken is greater than 0.1 sec, The boy will hear the echo