Question

A pebble is dropped freely in a well from its top.it takes the 20s for the pebble to reach the water surface in the well. Taking g=10ms^2 and speed of sound=330ms^1, find :
(i) the depth of water surface, and (ii) the time when echo is head after the pebble is dropped.

Answer 1

Answer:

depth: 2km

time: 20+6.6=26.6 sec

Explanation:

use free fall equation to find depth

to find time taken by sound to travel depth

add thi time to 20 sec