Question

A man starts from rest and moves with constant acceleration towards a hill which is 648 metres away he fires a gun at the instant of starting and hears it after 4 seconds. Velocity of sound is 320 metre per second. What is his acceleration ?

Answer 1

Given that,

Distance = 648 m

Velocity of sound = 320 m/s

Suppose, The man reaches the hill in 2 sec.

We need to calculate the velocity of man

Using formula of velocity

$v=\dfrac{d}{t}$

Where, v = velocity

d = distance

t = time

Put the value into the formula

$v=\dfrac{648}{2}$

$v=324\ m/s$

We need to calculate the acceleration of man

Using equation of motion

$v=u+at$

Put the value into the formula

$324=0+a\times2$

$a=\dfrac{324}{2}$

$a=162\ m/s^2$

Hence, The acceleration of man is 162 m/s².