Physics
posted by Anonymous .
A softball of mass 0.200 kg that is moving with a speed of 8.2 m/s collides headon and elastically with another ball initially at rest. Afterward the incoming softball bounces backward with a speed of 3.9 m/s.
1. Calculate the velocity of the target ball after the collision.
2. Calculate the mass of the target ball.

Conservation of momentum leads to
.2kg*8.2m/s=.2kg*(3.9)m/s + Mass*V
Solve for V in therms of all the other.
Then put that into this for V
conservation of energy.
1/2 .2 *8.2^2=1/2 .2*(3.9)^2 + 1/2 MV^2
then solve for mass, after that, go back and solve for V