A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Giving g = 10 ms^-2 and speed of sound = 340 ms^-1.

Given:

Distance covered by stone, s = 500 m

Initial speed, u = 0 (As the stone is initially at rest)

Time taken, t =?

Acceleration, g = 10 m/s²

We know the second equation of motion,

s =
Putting the values in the above equation we get:-

500 = 5 × t²

t²=

t² = 100

t = √100 = 10 sec

∴ the time taken by the stone to reach the pond = 10 s ..(i)

Now, we know that,

Speed of sound =

340 =

Time taken by sound to travel 500m upwards =

= 1.47 s ..(ii)

So, the required time at which splash is heard at the top = 10 s + 1.47s = 11.47 seconds

A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Giving g = 10 ms-2 and speed of sound = 340 ms-1.