Question

If you drop a little stone into a hole to figure out it’s depth ,how deep is the hole of you hear the plung after 3 seconds

A 30m
B 45m
C 60m
D 75m
E 90m

Answer 1

always accleration of anything is 10m/s when it is drop from height so answer is A.30m

Answer 2

B 45m

as during free fall acceleration of stone= 9.8ms^(-2)

and 45 m distance is negligible wrt velocity of sound