An imperfect spring has a restoring force F that depends on the displacement x from equilibrium as in the graph shown below.
The slope of the curve for x<-d and x>d is a constant -k. A mass m is attached to the spring and released from rest at the position x=A, where A>d. What is the period of the subsequent motion?
Answer Choices
A. T=\sqrt{\frac{m}{k}}\left(2 \pi+\frac{2 d}{A}\right)
B. T=\sqrt{\frac{m}{k}}\left(2 \pi+\frac{2 d}{A-d}\right)
C. T=\sqrt{\frac{m}{k}}\left(2 \pi+\frac{4 d}{A-d}\right) \leftarrow CORRECT
D. T=\sqrt{\frac{m}{k}}\left(2 \pi+\frac{\pi d}{A-d}\right)
E. T=\sqrt{\frac{m}{k}}\left(2 \pi+\frac{2 \pi d}{A-d}\right)
