A body of mass
m
is tied to one end of a string of length
l
and revolves vertically in a circular path. At the
lowest point of circle, what must be the
K.E.
of the body so as to complete the circle [RPMT 1996]
(a)
5 mgl
(b)
4 mgl
(c)
2.5 mgl
(d)
2 mgl