Question

If the velocity of a body becomes doubled then its kinetic energy will

Answer 1

Kinetic Energy before doubling the velocity.

$k.e \: = \frac{1}{2} m {v}^{2}$

and, Now v = 2v

Kinetic Energy would be.

$k.e = \frac{1}{2} m {(2v)}^{2} \\ \\ k.e = 2m {v}^{2}$

Ratio :

$= \frac{ \frac{1}{2} m {v}^{2} }{2m {v}^{2} } \\ \\ = \frac{m {v}^{2} }{4m {v}^{2} } \\ \\ = \frac{1}{4}$

Therefore, Kinetic energy would become 4 times.