A dish is made from a section of a hollow glass sphere. The dish, fixed to a horizontal table, contains a small solid ball of mass 
, as shown in the figure below.
The horizontal displacement of the ball from the centre C of the dish is 
. Initially, the ball is held at rest with distance 
. The ball is then released. The variation with time 
of the horizontal displacement of the ball from point C is shown in the graph below.
The motion of the ball in the dish is simple harmonic with its acceleration 
given by the expression
where 
is the acceleration of free fall and 
is a constant that depends on the dimensions of the dish and the ball.
Some moisture collects on the surface of the dish so that the motion of the ball becomes lightly damped. On the axes of the graph above, draw a line to show the lightly damped motion of the ball for the first 
after the release of the ball.
