Question

A ball of mass m attached to a string swings in a vertical circle, as shown. What is the tension in the string when the ball is at the top of the circle?

Answer 1

At the top the forces on the mass are the weight and the tension. Then by Newton's second law we have that the total force Fc is:

$\begin{gathered} F_c=T+mg \\ T=F_c-mg \end{gathered}$

Therefore the answer is b.