Question

a body is dropped into a well 19.6 metre deep after how much time the sound will be here by the person who had thrown the body velocity of sound is 300 metre per sec​

Answer 1

Explanation:

height , h = 19.6 m

gravity , g = 9.8 m/s^2

initial velocity , u = 0 m/s

time , t = ???

Using 2nd Equation of Motion ,

$h = ut + \frac{1}{2}g {t}^{2}$

$19.6 = \frac{1}{2} \times 9.8 \times { t }^{2}$

$t = 4 \: s \:$

$distance = \frac{speed \: of \: sound \: }{time}$

$time = \frac{distance}{speed} = \frac{19.6}{300} = 0.065 \: s$

Total time taken = 4 + 0.065 = 4.065 seconds

Therefore , it is your answer.

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