INSTRUCTOR: Calculate the force required to produce 15 newton meters of torque at an angle of 30 degrees from a 150-centimeter rod. Now, we know that the magnitude of torque, that is, the Greek letter tau, equals the magnitude of r multiplied by the magnitude of F, the force, multiplied by sine of theta will give us-- well, these two things are related.

The magnitude of the torque is equal to the magnitude of r multiplied by the magnitude of the force multiplied by the sine of the angle theta. And we know a lot of this information. We know what the torque is. The magnitude of torque is 15 newton meters. So we have 15 newton meters equals r, which is not 150 centimeters. It is 1.5 meters.

The force is what we don't know. So we don't know the magnitude of the force in this question. And we know that sine of a 30-degree angle.

OK, so putting our information in this equation, we have 15 equals 1.5 times magnitude of our force multiplied by the sine of 30 degrees. The sine of 30 degrees is 0.5, so this means we have the equation 15 equals 0.75 times the magnitude of force. And if we divide by 0.75, we have the magnitude of force is equal to 20 newtons.