A small sphere of mass m is connected by a string to a swivel at O and moves in a circle...

A small sphere of mass m is connected by a string to a swivel at O and moves in a circle of radius r on the smooth plane inclined at an angle θ with the horizontal. If the sphere has a velocity u at the top position A, determine the tension in the string as the sphere passes the 90° position B and the bottom position C.