Problem 2: Suppose the massless rod in the discussion of the nonlinear pendulum is a string of length l. A mass m is attached to the end of the string and the pendulum. is released from rest at a small displacement angle 60 > 0. When the pendulum. reaches the equilibrium position, the string hits a nail and gets caught at this point 1/4 above the mass. The mass oscillates from this new pivot point as shown in the gure. (a) Construct and solve a linear initial-value problem that gives the displacement angle, denote it mm, for 0 S t