-A car is driving in the negative direction, getting faster and faster as it goes. Is the car's velocity positive, negative, or zero? Is the car's acceleration positive, negative, or zero?
-A ball is tied to the bottom of a box, and you are pulling them up using a rope attached to the top of the box as shown below. You’re pulling such that they move up at a constant velocity. Consider your system to be the box.
Is the work done by you on the system positive, negative, or zero? Which forces should appear on a free body diagram for the box? Select all that apply: weight force from Earth on box, weight force from Earth on ball, weight force from ball on box, tension force from bottom rope on box, tension force from top rope on box, tension force from bottom rope on ball, force of person on rope.
