**Q2: **

Two objects, I and II, collide. Object I has a
mass of 1.2 kg and object II has a mass of
0.75 kg. Object I has a speed of
1.4 m/s
before the collision and object II has a speed of 1.8 m/s
before the
collision. After the collision, object II has a speed of 2.1 m/s.

If the collision is perfectly elastic, what is the speed of object I after the collision?

If the collision is not perfectly elastic, what must the
speed of object I after the collision be less than?

If the collision is not perfectly elastic, what is the
minimum value of the speed of object I after the collision?

**Q3: **

Two objects, I and II, collide. Object I has a
mass of 0.25 kg and object II has a mass of 0.45 kg. Object I has a speed of
2.8 m/s before the collision and object II has a speed of 3.3 m/s before the
collision. The collision is inelastic, dissipating of the kinetic energy of
the objects. After the collision, object I has a speed of 1.8 m/s.

What is the speed of object II after the collision?

What is the ratio of the kinetic energy of object I before
the collision to its kinetic energy after the collision?

What is the ratio of the kinetic energy of object II before
the collision to its kinetic energy after the collision?