An object is suspended from a vertical spring as shown in the figure below.
The object is displaced vertically and then released so that it oscillates, undergoing simple harmonic motion. The graph below shows the variation with displacement 
of the energy 
of the oscillations.
The kinetic energy, the potential energy, and the total energy of the oscillations are each represented by one of the lines P, Q, and R.
State the energy that is represented by each of the lines P, Q and R.
A light card is attached to the object. The object is displaced with the same initial amplitude and then released. During each complete oscillation the total energy of the system decreases by 
of the total energy at the start of that oscillation. Determine the decrease in total energy, in 
, of the system by the end of the first 6 complete oscillations.
.
