00:01
So all of this is actually just a conservation of angular momentum problem.
00:06
So you have the initial angular momentum equals the final angular momentum.
00:11
And this is always true.
00:13
And so our initial angular momentum before the bug decides to crawl to the other end of the rod is 1 .005 times 10 to the negative 3rd kilograms.
00:35
Grams times meters squared.
00:38
And that's our moment of inertia.
00:41
And then it's multiplied by our angular velocity, 0 .83, 3 per second.
00:50
And then this will all equal mass final times angular momentum final.
00:57
Now this mass final will actually just be that moment of inertia that we're given.
01:04
And then we're going to add the mass of the bug.
01:07
And so what you get for all of that will be 1 .05 times 10 to the negative third kilograms meter squared plus 5 times 10 to the negative third kilograms.
01:32
And then this is going to be multiplied right here by the length of that rod squared.
01:40
Because that will get us the same units as the moment of inertia...