00:01
All right, so first question says we have a solid cylinder with a mass of five kilograms and a radius of 30 centimeters.
00:11
And it's subject to a torque of 40 newton meters.
00:16
And we want to know what's the angular acceleration.
00:18
So the angular acceleration is going to be the torque divided by the moment of inertia.
00:22
That falls from the definition of torque.
00:25
And the moment of inertia for a solid cylinder rotating about its axis, it's just going to be like one.
00:30
1 1⁄2mr squared.
00:32
So if we plug that into this equation, we have 40 newton meters divided by 1⁄2x 5 kilograms times 0 .3 meters squared.
00:44
And this gives us something like if we're rounding 178 radians a second squared.
00:52
So, of course, that's choice d.
00:55
Number two, when an object is in static equilibrium, this means that c, net force and the net torque are zero so that there's no motion because that's what static means.
01:07
Next up, we have a solid cylinder with a mass of five kilograms and a radius of 30 centimeters, so basically the same cylinder we had in the first problem.
01:19
And it's rolling on a surface and it's got a linear velocity of two meters a second...