Question

19. A pebble is dropped freely in a well from its top.
It takes 20 s for the pebble to reach the water
surface in the well. Taking g = 10 m s
10 m s-2 and speed of
sound = 330 m s-/, find : (i) the depth of water surface,
and (ii) the time when echo is heard after the pebble is
dropped.​

Answer 1

Answer:

Time is taken for pebble to reach the water surface = 20 s. Therefore, the total time taken to hear the echo after the pebble is dropped = 20 + 6.1 = 26.1 s.