Chapter 3.1, Problem 1bT

In a separate experiment, two hands push horizontally on the block. Hand 1 does positive work and hand 2 does negative work $\left(W_{{\text{H}}_1}>0;W_{{\text{H}}_2}<0;\right)$ .

For each of the following cases, draw a free-body diagram for the block that shows all the horizontal and vertical forces exerted on the block. Tell whether the sum, $W_{{\text{H}}_1}+W_{{\text{H}}_2}$ , is positive, negative, or zero.