Answer
See work.
Work Step by Step
a. Use equation 6.2. The angle between the force and the displacement is $0^{\circ}$.
$$(2.40N)(1.50m)cos0^{\circ}=3.60 J$$
b. Use equation 6.2. The angle between the force and the displacement is $180^{\circ}$.
$$(0.600N)(1.50m)cos0^{\circ}=-0.900 J$$
c and d. Use equation 6.2. The angle between the force and the displacement is $90^{\circ}$. The cosine is zero so there is no work done. Whenever a force acts perpendicular to the direction of motion, its contribution to the net work is zero.
e. Add up the work done by all 4 forces to find 2.70 J.
