Question

work - mu
you carry a book on your head to the bookcase, which of the following describes the total work done after you stopped moving?
you do no work on the book
you do work on the book in both the horizontal and vertical directions.
you do work on the book in the vertical direction.
you do work on the book in the horzontal direction

Explanation:

Work is calculated as \(W = F\times d\times\cos\theta\) (where \(F\) is force, \(d\) is displacement, and \(\theta\) is the angle between force and displacement). When you stop moving, \(d = 0\). So, \(W=F\times0\times\cos\theta = 0\).

Answer:

You do no work on the book.