Question

If the velocity of a body becomes two times its initial velocity, then by how many times will its kinetic energy increase

Answer 1

Let the initial velocity be v and final velocity be v'.

Then, initial kinetic energy=1/2 mv².

And, final kinetic energy=1/2 mv'²

=1/2 m(2v)²

=1/2 m × 4v²

=4 × 1/2 mv²

=4 × E₁.

∴ The kinetic energy becomes 4 times when velocity is doubled.