00:01
So in this problem, we have an incline.
00:05
And for the first situation, we have a sphere rolling down from the top.
00:10
So this is a sphere.
00:12
And the second case, we have a block running down.
00:16
It's not rolling down.
00:17
Just a slide down from the top.
00:20
And so for the first case, we say that the sphere is not sliding.
00:27
It's purely rotation.
00:29
It rotate, i mean, there is no sliding between the, sphere and this incline.
00:37
And for the second case, there is no friction between the surface and the block.
00:42
Okay.
00:43
So we want to determine which one reaches the bottom first.
00:47
So let's suppose the velocity of the sphere is v.
00:51
Is vs.
00:51
Okay.
00:53
And because there is no there is no slipping, right? so we can determine the angular velocity of the sphere.
00:59
That is a vs over r...