This is something I am learning on my own. However, this problem is confusing me: Red is a girl of mass m who is taking a picnic lunch to her grandmother. She ties a rope of length R to a tree branch over a creek and starts swing from rest at point A, which is a distance R/2 lower than the branch. What is the minimum breaking tension for the rope if it is not to break and drop Red into the creek? What is this breaking tension thing? I don't quite understand what I am suppose to calculuate.