Question

A stone is dropped into a lake from a tower 500m high.what is the time taken by the sound of the splash to be heard by a man on the tower ?(velocity of sound = 340 m/s)

Answer 1

Here time will take to reach the stone in the water and time taken by sound to reach the man
let t1 is the time taken by the stone to reach water
S=ut+1/2at1^2
here u=0
a=g
s=500
so we get 500=1/2 g×t1^2
take g=10(aprox)
2×500/10=t1^2
t1=10
The splash sound should travel 500 m to reach the man with 340 velocity
t2=500/340
t2=1.47
so total time taken to reach the splash sound in the man=10+1.47=11.47seconds