2. A 38kg child is at the top of a slide that is 2.1m tall. (a) If there is no friction, how fast will they be moving when they reach the bottom of the slide?
(b) If they lose 250.0J of energy to sound, heat, and friction, how fast will they be moving when they reach the bottom?

3. A 0.850 kg air-track glider moving at 1.75 m/s bumps into a 1.45 kg glider initially at rest.
(a) If the collision is elastic, find the total kinetic energy after collision.
(b) If the collision is completely inelastic, find the total kinetic energy after collision.