$($a$)$ What is the minimum height from which you can release the ball so that it will go around the loop$-$the$-$loop without falling off?

For part $($b$),$ assume that the ball is released from rest at a height of $28\mathrm{.}53$ cm above the bottom of the loop.

$($b$)$ What is the magnitude of the horizontal force on ball when it is at a height $11$ cm going up the hoop?

$($c$)$What is the direction of the net force on the ball at the top of the hoop?

f$=$ x$+$