A mass m = 7.8 kg hangs on the end of a massless rope L = 1.83 m long. The pendulum is held horizontal and released from rest.
Now a peg is placed 4/5 of the way down the pendulum's path so that when the mass falls to its vertical position it hits and wraps around the peg. As it wraps around the peg and attains its maximum height it ends a distance of 3/5 L below its starting point (or 2/5 L from its lowest point).
What is the magnitude of the tension in the string at the top of the new path (directly above the peg)?