Work, Energy and Power

A bob of mass m is suspended
by a light string of length L . It is imparted a
horizontal velocity vo
at the lowest point A
such that it completes a semi-circular
trajectory in the vertical plane with the string
becoming slack only on reaching the topmost
point, C. This is shown in Fig. 5.6. Obtain an
expression for (i) vo
; (ii) the speeds at points
B and C; (iii) the ratio of the kinetic energies
(KB
/KC
) at B and C. Comment on the nature
of the trajectory of the bob after it reaches
the point C.