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A ball of mass m is attached to a light inextensible string of
length l. The ball is whirled around so that it moves in a
horizontal circle with constant angular speed w. Find
the angle q between the string and the vertical.
Show that the angle q is given by
. Now
increase the angular velocity. What happens to the ball? What
is the smallest angular velocity with which the ball can whirl in a
circle on the end of the string in this way?