Problem:
For spring break, you travel back home to visit your parents. While trying to relax at their house, your dad makes you help him clean the garage. He asks you to move a 50kg box from one side of the garage to the other. The box is too awkward to carry, so you attach an old rope to the box so you can pull it across the floor. You pull the box at an angle of 30* and the static coefficient of friction between the box and the floor is 0.25.
(a) Draw a free body diagram for the box while you are pulling on the rope, but the box doesn't move.
(b) If you pull the rope with a force of 100N at the same angle, does the box move? (Prove it)
(c) Because the rope has been in the garage for a very long time, it will break if it experiences a force greater than 150N. What is the minimum amount of force you need to pull to get the box moving? Is the rope strong enough to get the box moving if you pull at this same angle? (You may want to rethink your answer to b)
(d) Without cleaning the dirty garage floor, or otherwise introducing anything between the two surfaces, how could you decrease the force due to friction? Explain!