Question

A stone is dropped 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‐²...?????!!!
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Answer 1

Explanation:

time taken for stone to reach the pond

=distance/speed

=500/10

=50 seconds

time taken for sound to reach=500/340

=1.47 seconds

Total time=50+1.47

=51.47 seconds

Answer 2

AnsweR :-

11.47 s

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Procedure:-

When the stone waa dropped from the top of tower it took $t_1$ time to strike down. The sound takes $t_2$ time to travel upward.

Now here ,

$H = 500m$

$G = 10 ms^{-2}$

$For\: stone\:u = 0$

As stone is freely falling, time $t_1$ is given by -

$\large\ h = ut_1 + 1/2gt^{2}_1$

$\large\ 500 = 0 \times t_1 + 1/2 \times (10)\times t_1^{2} = 5t_1^{2}$

$\large\ t_1^{2} = \frac{500}{5}= 100\: or\: t_1 = \sqrt {100}= 10s$

Now the sound of splash travels with a constant speed

$v = 340 m/s-1$

$\large\ time\: ,t_2 = \frac{h}{v} =\frac{500}{340} = 1.47s$

$\therefore$ Time of hearing splash =$t_1 +t_2 = 10 + 1.47 = 11.47s$

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