Question

If the velocity of a body is doubled, what will be the change in its K.E

Answer 1

the kinetic energy is given as

KE = (1/2)mv²

so, if the velocity is doubled the kinetic energy becomes

KE' = (1/2)m(2v)² = 4[(1/2)mv²]

so,

KE' = 4KE

thus, kinetic energy increases four times.