Question

The K.E of a body becomes 4 times its initial value. The new linear momentum will be :

• A. same as intial value
• B. four times the intial value
• C. twice the intial value
• D. eight times the intial value

Answer 1

The correct option is C twice the intial value

Let P,M and E is the momentum,mass and energy of the body.
$P=\sqrt{2mE}$
$P^{\prime }=\sqrt{2m\times 4E}$
$\frac{P^{\prime }}{P}=\sqrt{\frac{2m\times 4E}{2mE}}$
$P^{\prime }=2P$
hence,option C is correct.