Chapter 3.1, Problem 1cT

Shown at right is a side-view diagram of the displacement, $\Delta \stackrel{\to }{s_o}$ , that a block undergoes on a table when pushed by a hand. The horizontal force on the block by the hand, $\Delta {\stackrel{\to }{F}}_{\text{BH}}$ , is also shown.

1. Suppose instead that a hand pushes with a force of the same magnitude, $\Delta {\stackrel{\to }{F}}_{\text{BH}}$ , as before but now at an angle below the horizontal, as shown in the side-view diagram at right. Is the work done by the new force greater than, less than, or equal to the work done by the original force?

Explain how you used the definition of work to obtain your answer.

Suppose instead that a hand pushes with a force of the same magnitude, $\Delta {\stackrel{\to }{F}}_{\text{BH}}$ , as before but instead does zero work. In the space at right, draw an arrow to represent the direction of the force by the hand in this case.