00:02
This problem will cover rotational kinetic energy.
00:06
Say we have a basketball, which is rolling without slipping across the floor.
00:15
Let's approximate the basketball as a hollow sphere.
00:20
Want to note what fraction of its kinetic energy is rotational kinetic energy.
00:28
So first, let's write out the total kinetic energy.
00:31
The total kinetic energy is a sum of the translational part plus the rotational part.
00:45
The translational part, as we'll know, is 1 half mv squared.
00:52
The rotational part is 1 half i omega squared.
00:57
This is where the shape of the ball comes in.
01:00
For a spherical shell, i, the rotation of inertia, the moment of inertia, is 2 thirds m r squared...