A student librarian picks up a 2.2 kg book from the floor to a height of 1.20 m. He carries the book 7.6 m to the stacks and places the book on a shelf that is 0.35 m above the floor. How much work does he do on the book?
The work done on the book is equal to the force applied to the book multiplied by the distance it is moved. In this case, the force applied is equal to the weight of the book, which is 2.2 kg x 9.8 m/s^2 = 21.56 N. The total distance the book is moved is 8.95 m (1.20 m + 7.6 m + 0.35 m). Therefore, the work done on the book is 21.56 N x 8.95 m = 193.2 J.
