Question

Calculate the kinetic energy of a body of mass $20kg$ moving with velocity of $0.1m/s$. How the kinetic energy will change if the velocity of the body be doubled ?

Answer 1

Given:

Mass of the body: $m=20kg$

Velocity of the body: $v=0.1m/s$

$K.E=\frac{1}{2}m{v}^2=\frac{1}{2}\times 20\times {0.1}^2=0.1J$

When the velocity of the body is doubled -

$newv=2\times 0.1m/s=0.2m/s$

$newK.E=\frac{1}{2}m{v}^2=\frac{1}{2}\times 20\times {0.2}^2=0.4J$

New K.E becomes $4times$ the old K.E.