# physics

posted by
**Joey**
.

A hollow sphere of radius 0.30 m, with rotational inertia I = 0.072 kg m2 about a line through its center of mass, rolls without slipping up a surface inclined at 25° to the horizontal. At a certain initial position, the sphere's total kinetic energy is 45 J.

(a) How much of this initial kinetic energy is rotational?

1 J

(b) What is the speed of the center of mass of the sphere at the initial position?

2 m/s

Now, the sphere moves 1.0 m up the incline from its initial position.

(c) What is its total kinetic energy now?

3 J

(d) What is the speed of its center of mass now?

4 m/s