Question

A body of mass 10 kg is released from a point where it possesses an energy of 1920.8J. Find the velocity with which it hits the ground.

Answer 1

Mass of the body, m $=$ 10 kg
When the body is released from a certain height, the total potential energy gets converted into kinetic energy when it reaches the ground.
Given, kinetic energy (K.E.) $=$ 1920.8 J
Velocity of the body (v) $=$?
$K.E.=\frac{1}{2}m{v}^2$
$\Rightarrow 1920.8=\frac{1}{2}\times 10\times v^2$

$\Rightarrow v^2=\frac{192.8}{5}=384.16$
$\Rightarrow v=19.5m{s}^{-1}$
Therefore, the velocity of the body when it reaches the ground is 19.6 m s${}^{-1}$