Question

When a bullet is fired from a gun
a) Kinetic Energy of bullet is more than that of gun
b) acceleration of bullet is more than that of gun
c) momentum of bullet is more that of gun
d) velocity of bullet is more than that of gun

• A. only a & b are true
• B. only b & c are true
• C. a, b & d are true
• D. a, b, c & d are true

Answer 1

The correct option is C a, b & d are true

Let $p$ be magnitude of momentum.

1) $K.E=\frac{1}{2}m{v}^2$

$=\frac{1}{2}\frac{p^2}{m}$

So $K.E{.}_{bullet}>K.E{.}_{gun}$

2) Force will be same on bullet & gun

so, acceleration of bullet > gun because $m_{bullet}<m_{gun}$

3) Momentum will same in both cases.

4) $v=\frac{p}{m}$ which is more for bullet.