A long strip of springy steel is clamped at one end so that the strip is vertical. A mass of 
is attached to the free end of the strip, as shown in the figure below.
The mass is pulled to one side and then released. The variation with time 
of the horizontal displacement of the mass is shown in the graph below.
he mass undergoes damped simple harmonic motion.
Use the graph above to determine the frequency of vibration of the mass.
Hence show that the initial energy stored in the steel strip before the mass is released is approximately 
.
.
