a ball of mass 3 kg is moving with a velocity of 10 m/s. This ball collides with a second ball of mass 0.5 kg that is at rest. After the collison, the first ball is at rest. What is the velocity after the collison of the second ball if the collison is inelastic?

Use the momentum conservation formula:

m₁∆v₁ + m₂∆v₂ = m₁∆v₁' + m₂∆v₂'

The initial velocity of the second ball is 0, since it starts from rest, and the final velocity of the first ball is 0 since it ends at rest:

3*10 + 0.5*0 = 3*0 + 0.5∆v₂'

∆v₂' = 60m/s