Answer to Question #201077 in Mechanics | Relativity for karen

Question

In problem 21, what is the combined moment magnitude of the forces P and Q about a. x-axis; b. y-axis; and c. z-axis 

Answer 1

The net external effect of a couple is that the net force equals zero and the magnitude of the net moment equals F *d. Since the moment of a couple depends only on the distance between the forces, the moment of a couple is a free vector.