There is a step of height `h` on an incline plane. The step prevents a ball of radius R from rolling down.
(a) If the inclination `(theta)` of the incline is increased gradually, at what value of `theta` the ball will just manage to climb the step?

(b) Does the gravitational potential energy of the ball increases or decreases as it climbs the step ?

Answer

(a) `cos theta = (R - h)/(R)`
(b) Decreases