Question

A 0.20-kg ball on a string is whirled on a vertical circle at a constant speed. When the ball is at the three o'clock position, the string tension is 16 N. Find the tensions in the string when the ball is at twelve o'clock and at the six o'clock positions.

Answer 1

at three oclock, Tension= mv^2/r

then at 12 oclock,
tension= mv^2/r-mg
and at six...
tension= mv^2/r + mg

Answer 2

How can I find the v and the r for 3 o'clock.