If the mass of the object is doubled without changing its velocity then what will be the change in its kinetic energy and linear momentum?

Given:
New mass, m'= 2m

To find: 
Final Kinetic energy, K.E'
Final linear momentum, p'

Solution: 
We know that,
KE = $\frac{1}{2}{\mathrm{mv}}^2$           ....(1)
 $\mathrm{p}= \mathrm{mv}$                  ....(2)
Since there is no change in the velocity of the body, v will remain the same.

$\mathrm{KE}\text{'}= \frac{1}{2}\mathrm{m}\text{'}{\mathrm{v}}^2$= 2 $\times \frac{1}{2}{\mathrm{mv}}^2$ = 2KE
$\mathrm{p}= \mathrm{m}\text{'}\mathrm{v}$ = $2\times \mathrm{mv} = 2\mathrm{p}$

Therefore, both kinetic energy and linear momentum will become twice.