The differential equation of motion for an undamped system with constant external forces, from Eq. (20.45), is Mq¨ + K q = F, where F is the constant generalized force. Prove that the plot of q?/p versus q is the circle shown, where p is the natural circular frequency of the system. (Note: The circle is called the phase plane plot of the system. Plots of this type can be very helpful in describing the behavior of complex, single-degree-of-freedom systems.
