Question

10. A bullet of 20gm is shot from a gun of 2kg at a velocity of 100m/s find
out the recoil velocity of the gun. (5m)​

Answer 1

Answer:

-0.5m/s

Explanation:

Mass of bullet, m=100g=1000100kg=101kg

Velocity of bullet, v=100ms−1

Mass of gun, M=20kg

Let recoil velocity of gun =V

Before firing, the system (gun+bullet) is at rest, therefore, initial momentum of the system =0

Final momentum of the system = momentum of bullet + momentum of gun

=mv+MV=101×100+20V=10+20V

Applying law of conservation of momentum, Final momentum = Initial momentum

i.e., 10+20V=0

20V=−10

or V=−2010=−0.5ms−1.

Negative sign shows that the direction of recoil velocity of the gun is opposite to the direction of the velocity of the bullet.