Question

a body of mass 5kg is having momentum 50kgm/s.what is its kinetic energy?​

Answer 1

Kinetic energy = 250 J

Given

Mass of the body = 5 kg

Momentum of the body = 50 kg.m/s

To Find

Kinetic Energy

Formula Applied

• K = Kinetic energy
• m = mass
• v = velocity
• P = momentum

$\bf K=\dfrac{1}{2}mv^2\\\\\to \rm K=\dfrac{mv^2}{2}\\\\\to \rm K=\dfrac{mv^2}{2}\times \dfrac{m}{m}\\\\\to \rm K=\dfrac{(mv)^2}{2m}\\\\\to \bf K=\dfrac{P^2}{2m}\\\\\rm \because\ P=mv$

Solution

Mass , m = 5 kg

Momentum , P = 50 kg.m/s

Kinetic Energy , K = ? J

Apply formula ,

$\bf \to K=\dfrac{P^2}{2m}\\\\\to \rm K=\dfrac{(50)^2}{2(5)}\\\\\to \rm K=\dfrac{2500}{10}\\\\\to \bf K=250\ J\ \; \pink{\bigstar}$

So , Kinetic energy = 250 J