Question

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? Given, g = 10 m s^–2 and speed of sound = 340 m s^–1.

Answer 1

Height of the tower, s = 500 m

Velocity of sound, v = 340 m s⁻¹

Acceleration due to gravity, g = 10 m s⁻²

Initial velocity of the stone, u = 0 (since the stone is initially at rest)

Time taken by the stone to fall to the base of the tower, t₁

According to the second equation of motion:

Now, time taken by the sound to reach the top from the base of the tower,

Therefore, the splash is heard at the top after time, t

Where, t = t₁ + t₂ =10 + 1.47 = 11.47s