Step 1: Given that:
Mass of bullet(mbullet) = 10g = 101000kg=0.01kg
Velocity of the bullet(ubullet) = 400ms−1
Mass of freely suspended wooden block(M) = 900g = 9001000kg=0.9kg
Initial velocity of the wooden block(ublock)= 0
Step 2: Formula used:
According to law of conservation of momentum,
The total momentum of the bodies before collision= Total momentum of the bodies after collision
Mathematically; m1u1+m2u2=m1v1+m2v2
Momentum= mass× velocity of the body
Step 3: Calculation of velocity of the block after collision:
mbulletubullet+Mublock=(mbullet+M)vblock
⇒0.01kg×400ms−1+0.9kg×0=(0.01kg+0.9kg)vblock
⇒0.91vblock=4
⇒vblock=40.91
⇒vblock=4.40ms−1
Thus,
The velocity of the wooden block is 4.40ms−1 .