Question

a 100 g mass moving at 6 m/s collides with another 100 g mass at rest, find the velocity of second mass after the collision ,if the first comes to rest.

Answer 1

mass of object 1, m1= 100 g
initial velocity of object 1, u1= 6 m/s
final velocity of object 1, v1= 0 m/s

mass of object 2, m2= 100 g
initial velocity of object 2, u2= 0 m/s
final velocity of object 2, v2= ?

     From the law of conservation of momentum, we have
   
        total initial momentum = total final momentum
                       m1u1 + m2u2 = m1v1 + m2v2
                   
       ⇒ 100 g × 6 m/s + 100 g × 0 m/s = 100 g × 0 m/s + 100 g × v2
       ⇒ 600 gm/s + 0 gm/s = 0 gm/s + 100g × v2
       ⇒ 600 gm/s = 100g ×v2
       ⇒ 6 m/s = v2
       ⇒ v2 = 6m/s

Therefore, the velocity of second mass after the collision is 6 m/s .