Notifications
Clear all
0
09/01/2021 12:10 pm
Topic starter
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 ms-1.
1 Answer
0
09/01/2021 12:16 pm
Here, height through which the stone falls, h = 500 m
Speed of sound, v = 340 ms-1, g = 10 ms-2
If t is the time taken by the stone to fall through h, then
h = \(\frac{1}{2}gt^2\) or t = \(\sqrt{\frac{2h}{g}}\)
t = \(\sqrt{\frac{2 \times 500}{10}}\) = 10 s
Further, if 't' is the time taken by sound (produced as a result of splashing) to travel to the top of the tower,
t' = \(\frac{h}{v}\) = \(\frac{500}{340}\) = 1.47 s
Time after which the splash is heard at the top of the tower
= t + t' = 10 s + 1.47 s = 11.47 s