Question

A mass on a string. Practice Exam Question.

Answer 1

A mass m is attached to a string of length l and has a speed of v(0) at the lowest point. Find the tension of the string at the angle theta and the velocity v. Use conservation of Energy to solve for the speed at the angle theta in terms of the speed at the lowest point v(0). If the mass swings through a full circle, the tension must be greater than zero
at the highest point. Find the resulting condition for the speed v(0)just need hints on how to start this.

Answer 2

If you resolve the forces along the radial direction (ie along the string) then they have to equal mv^2/l. That should give you the first part.