Question

A bullet of mass 10 gram is fired into block of wood of mass 390 gram lying on smooth surface. The wood than move at a velocity of 10m/s. What was the velocity of bullet​

Answer 1

Answer: The velocity of the bullet is 400 m/s.

Explanation:

Given that,

Bullet of mass = 10 gram

Block of wood of mass = 390 gram

Velocity of wood = 10 m/s

According to conservation of momentum

$P_{i} = P_{f}$

$m_{b}u_{b} + m_{w}v_{w} = (m_{b}+ m_{w})v_{w}$

$10 gram\times u_{b} + 0= 400 gram \times 10 m/s$

$u_{b} = 400 m/s$

Hence, the velocity of  the bullet is 400 m/s.