Question

question 21
1 pts
a light aluminum ball and a heavy lead ball of the same size roll down an incline. when they are halfway down the incline, they will have identical
inertias.
potential energies.
momentum.
kinetic energies.
none of the above
question 22
1 pts
a roller - skate at rest may have
speed.
energy.
momentum.
velocity.

Explanation:

For Question 21: Inertia depends on mass, potential energy depends on mass and height, momentum and kinetic energy depend on mass and velocity. Since the masses differ, and velocity is the same for both at the halfway - point of the incline, they have none of the above identical.
For Question 22: Speed and velocity are zero for a roller - skate at rest, and momentum is zero as it is mass times velocity. But it can have potential energy (e.g., gravitational potential energy if it is at a non - zero height), so it may have energy.

Answer:

Question 21: none of the above
Question 22: energy