A student investigates the motion of a cart rolling down an…

A student investigates the motion of a cart rolling down an incline and colliding with another cart at the bottom. The following data were collected: Part A – Motion Down the Incline The cart (mass = 0.40 kg) is released from rest at different heights. The velocity at the bottom is measured and the data is recorded as shown in the table below. Height (m) Velocity at Bottom (m/s) 0.15 1.6 0.25 2.2 0.35 2.7 Questions: Use the principle of conservation of energy to explain why the velocity increases with height. Compare the measured velocities to the theoretical prediction v=2ghv = \sqrt{2gh}​. Do they agree reasonably well? Part B – Collision at the Bottom After rolling down, the 0.40 kg cart collides head-on with a stationary cart of mass 0.60 kg. After the collision, the two carts stick together and move off with a velocity of 1.0 m/s. Questions: 3. Identify the type of collision (elastic, inelastic, or perfectly inelastic). Justify your answer. 4. Using momentum conservation, show how the final velocity of 1.0 m/s supports the data. 5. Is kinetic energy conserved in this collision? Explain briefly.

A figure skater is spinning with her arms extended. Her rota…

A figure skater is spinning with her arms extended. Her rotational inertia in this position is 2.0 kg·m2. She then pulls her arms close to her body, reducing her rotational inertia to 1.2 kg·m2. If her final angular velocity is 3.0 rev/s, what was her initial angular velocity when her arms were extended?