Solid sphere rolling along a track

[JessicaHelena]

Homework Statement

Please see the attached file.

Homework Equations

Ei = Ef

The Attempt at a Solution

I don't have an answer key provided, but I'd really like to verify that I'm right (or if I'm wrong, why). I think ti'd be (c) because assuming that due to inertia, B will continue going straight up (even though gravity will decelerate its motion). When it finally stops moving, it will have 0 KE, but assuming the energy is conserved, it should have the same amount of mechanical energy as it did in A. Since at A, the ball had only gravitational potential energy (mgh), at its highest point in air, it too should have mgh and thus the same height as point A.

Would that be right?

 

[Chestermiller]

No, it would not be right. Will the ball be rotating after it leaves the track?

 

[JessicaHelena]

@Chestermiller — ah, it'd keep rotating even when it's stopped moving vertically, and so with less KE available "initially", the mgh will be less as well and thus the height will be less than the original height. Is that better?

 

[Chestermiller]

@Chestermiller — ah, it'd keep rotating even when it's stopped moving vertically, and so with less KE available "initially", the mgh will be less as well and thus the height will be less than the original height. Is that better?

If I understand you correctly, yes.