Need help with part C

A $0\mathrm{.}275-kg$ object is swung in a vertical circular path on a string $0\mathrm{.}850$ m long as in the figure.

$($a$)$ What are the forces acting on the ball at any point along this path?

The tension force in the string, directed towards the rentor nfith $--...$

Score: $1$ out of $1$

Comment:

$($b$)$ Draw free$-$body diagrams for the ball when it is at the bottom of the circle and when it is at the top. $($Submit a file with a maximum size of $1$ Choose File no file selected

$($c$)$ If its speed is $6\mathrm{.}18\frac{m}{s}$ at the top of the circle, what is the tension in the string there?

Your response differs from the correct answer by more than $100\%.$ N

$($d$)$ If the string breaks when its tension exceeds $24\mathrm{.}8$ N $,$ what is the maximum speed the object can have at the bottom before the string breaks? $\frac{m}{s}$