question_answer

A stone is dropped into a lake from a lower 500m high. The sound of the splash will be heard by a man on the tower after a time of (velocity of sound in air = 350 m/s) (a) 21 s                                  (b) 10 s   (c) 11.4 s                              (d) 1 s

Answer:

Let\[{{t}_{2}}\]be the time taken sound to reach the surface \[{{t}_{2}}=\frac{h}{{{v}_{sound}}}=\frac{500}{350}=1.45s\approx 1s\]