Question

Block 1, of mass m1, moves across a frictionless surface with speed ui. It collides elastically with block 2, of mass m2, which is at rest (vi=0). (Figure 1) After the collision, block 1 moves with speed uf, while block 2 moves with speed vf. Assume that m1>m2, so that after the collision, the two objects move off in the direction of the first object before the collision.

Part B

What is the final speed uf of block 1?

Express uf in terms of m1, m2, andui.

uf = ?

Part C

What is the final speed vf of block 2?

Express vf in terms of m1, m2, andui.

vf = ?

Answer 1

a) C

b) ((m1-m2)/(m1+m2)) x (ui)

c) ((2m1)/(m1+m2)) x (ui)