A bullet of mass 0.01kg is fired with velocity of 200m/s in to a sack of sand of mass 9.99kg which is swinging from rope. At the moment the bullet hits, the sack has a velocity of 0m/s. Workout the velocity of bullet and sand just after the bullet hits the sack
The velocity of the bullet and the sand just after the bullet hits the sack can be calculated using the conservation of momentum.
Momentum of bullet before impact = 0.01kg x 200m/s = 2 kg m/s
Momentum of sand before impact = 9.99kg x 0m/s = 0 kg m/s
Total momentum before impact = 2 kg m/s
Momentum of bullet and sand after impact = 2 kg m/s
Momentum of bullet after impact = 0.01kg x Vb
Momentum of sand after impact = 9.99kg x Vs
0.01Vb + 9.99Vs = 2
Vb = 200 m/s
Vs = 0.2 m/s