Please help 3. A billiard ball of mass 0.500 kg is rolling along a frictionless pool table with a velocity of 3.5 m/s. It then strikes another billiard ball of equal mass, initially at rest, which moves in a straight line with a velocity of 2.8 m/s.

a) What is the velocity of the first ball after the collision?
b) Is the collision elastic, completely inelastic, or partially inelastic?

4. A truck of mass 2575 kg moving at 11.0 m/s runs into the back of a car that is at rest and has a mass of 825 kg. The two vehicles slide off together.

a) Assuming friction can be ignored, find the velocity of the two vehicles after the collision.
b) Is the collision elastic, completely inelastic, or partially inelastic?

5. A 0.115 kg hockey puck, moving at 35.0 m/s strikes a 0.265 kg octopus sitting on the ice, thrown there by a hockey fan. The puck and octopus slide off together (they stick together). Find the velocity of the puck and octopus.

6. A car of mass 565 kg has a velocity of +25.0 m/s. It strikes a truck of mass 785 kg that has a velocity of +12.0 m/s (in the same direction) from behind. The two vehicles stick together. Find the velocity of the two vehicles after the collision.

7. A red dynamics cart of mass 0.250 kg is rolling with a velocity of 2.0 m/s when it strikes a blue
dynamics cart of mass 0.750 kg that is initially at rest. After the collision, the blue cart has a velocity of +1.0 m/s.
a) Determine the velocity of the red cart after the collision.
b) Is the collision elastic, completely inelastic, or partially inelastic?