A 2.9 kg block slides along a frictionless surface at 1.3 m/s. A second block, sliding at a faster 5.0 m/s, collides with the first from behind and sticks to it. The final velocity of the combined blocks is 2.7 m/s.

Question

A 2.9  kg block slides along a frictionless surface at 1.3 m/s. A second block, sliding at a faster 5.0 m/s, collides with the first from behind and sticks to it. The final velocity of the combined blocks is 2.7 m/s.

What was the mass of the second block?

bobpursley · Answer

Conservation of momentum applies. M1*V1i+M2*V2i= (M1+M2)Vf solve for M2