Question

a a bullet of 0.10kg is moving with a velocity of 400m/s how much work will have to be done to stop it​

Answer 1

Answer:

This problem can be solved using conservation of momentum.

As before firing the bullet both the gun and the bullet were at rest, so the total momentum before firing is zero

after firing the velocity of bullet (v)= 400 m/s, say the velocity of gun is V

mass of bullet (m)= 10/1000 kg , mass of gun (M)= 5 kg

From momentum conservation,

0= mv + MV

V = - (m/M)*v

V = - (10\5000)*400 m/s

V = - 0.8 m/s (Negative sign indicates that velocity of gun and bullet is in opposite direction)