| We now take a ball that is free to rotate on a rough surface. Here friction on the track is needed to get the ball rolling, and it does NOT significantly slow the ball down. |
| We start with a straight line. | |
The ball is atop the track.
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The ball is recessed into the track.
|
| Getting a little more fancy, here's a cosine. | |
The ball is atop the track.
|
The ball is recessed into the track.
|