The friction force has the same magnitude as the resultant of the weight mg and the normal force N. The sum of friction, mg, and N is zero.
Work Step by Step
This is discussed on page 84 and shown in Figure 5.25.
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.