Question

Calculate the change that should be affected in the velocity of a body to maintain the same K.E, if mass of the body is increased to 4 times.

Answer 1

K.E = $\frac{1}{2}$ $m{v}^2⟹$ $v=\sqrt{\frac{2\times K.E}{m}}$.

K.E is same, mass increased 4 times,

$Newv=\sqrt{\frac{2\times K.E}{4\times m}}$ = $\frac{1}{2}\sqrt{\frac{2\times K.E}{m}}$ = $\frac{v}{2}$

Hence, velocity becomes halfed.