1. The problem statement, all variables and given/known data A 400-N child is in a swing that is attached to a pair of ropes 2.00 m long. Find the gravitational potential energy of the child-Earth system relative to the child’s lowest position when (b) the ropes make a 30.0° angle with the vertical 2. Relevant equations Ug=mgy 3. The attempt at a solution b.) Ug = 400N ⋅ 2m(1-cos30) Ug = 107J I understand everything about the problem (and was able to do the other parts of it without issue) except where the 1-cos30 comes from. Even drawing it out I just can't visualize where that is coming from. I originally thought that it would just be 2m(cos30) but the answer key says that is wrong.