A mass of 6 kg is tied to a 2 meter long rope and is swung in a vertical circle. At the bottom of the circle, the mass is moving at a speed of 16 m/s. What is the tension, in Newtons, in the rope after the mass has traveled to a point exactly halfway between the top and bottom of the circle? Note: the speed for this case is not constant, it is changing due to gravity so use conservation of energy to find the speed at any point on the circle. Also, ignore friction.

Question

A mass of 6 kg is tied to a 2 meter long rope and is swung in a vertical circle.  At the bottom of the circle, the mass is moving at a speed of 16 m/s.  What is the tension, in Newtons, in the rope after the mass has traveled to a point exactly halfway between the top and bottom of the circle?  Note:  the speed for this case is not constant, it is changing due to gravity so use conservation of energy to find the speed at any point on the circle.  Also, ignore friction.
 Please help !!!