A large box containing your new computer sits on the bed of your pickup truck. You are stopped at a red light. The light turns green and you stomp on the gas and the truck accelerates. To your horror, the box starts to slide toward the back of the truck. (Assume that the truck is accelerating to the right.)
Draw clearly labeled free-body diagram for the box. (The bed of the truck is not frictionless.)
The orientation of your vectors will be graded. The exact length of your vectors will not be graded but the relative length of one to the other will be graded.
Given:
F_road = reaction force to tires' backward push
n_ground = normal force
n_b = reaction to the normal force on the box from the truck
w_t = weight of the truck
f_k = the box's friction force on the truck bed