[McKay (OP)]

Coriolis effect - In a non-friction system, f I roll something along the surface of the planet from on of the poles to the equator, it will appear to move to the west, it will essentially stay behind the planets rotation and actually rotate it in the opposite direction. Now, if we add friction to the system, the planet will accelerate the ball. The question is - will the planet system as a whole slow down? As I understand it should work the same with a spinning ballerina, who rotates with arms pulled to chest, expands them straight out and slows herself rotating.

And the opposite - if we roll the ball from equator to pole in non friction system, it will "go ahead" the planet, as it has more energy/ speed than lower points of the planet. Then, if we ad friction, the planet will slow down the ball and and the whole planet system will accelerate again? (again the ballerina effect)

if the friction that accelerates the ball is a, say, piezoelectric crystal attached to the surface of the planet in with the ball smacks in to and when the ball strikes it, it not only accelerates (deceleration is just acceleration in the opposite direction anyway) the planet, but also generates electricity from the impact? What then? The electric energy eventually turns in heat and some of that will even radiate away from the planet, in space.
So.. the planet slows down .. because energy is somehow pumped out of its rotation or.. what?