The pendulum system in Figure 8.35 consists of a uniform thin rod of length l and a concentrated mass m at its tip. The friction at the pivot causes the system to be damped. When the angular displacement θ is not very small, the system is described by the nonlinear model
Assume, in consistent physical units, that ml2 = 1.5 , = 6.8. Two sets of initial conditions
are to be considered: (1) θ(0 ) = 10°, ( 0) = 0 , and (2) θ(0) = 20 °, (0) = 0. Using the RK4 method plot the two angular displacements θ1 and θ2 corresponding to the two sets of initial conditions versus 0 ≤ t ≤ 10 in the same graph. Angle measures must be converted to radians.
