00:01
In this problem, we have three forces acting on this circle, and we need to find the net torque on the system.
00:11
So the net torque is found by finding the torque from each individual force.
00:16
Force one is perpendicular to the disk, so that will actually have a torque of zero.
00:24
It won't cause any rotation whatsoever.
00:27
Torque two, the force from force two, we can find by take.
00:31
R cross f and since this is perpendicular, so it's tangent to the disk, we can say rf sign of 90 degrees, which is just one.
00:45
So then we get r times f times one or point to 27 times the magnitude of force 2, which is 7 newtons.
00:55
And we get a torque of 1 .89 newton meters counterclockwise, so that'll be positive...