$3.$ A small mass m $=0\mathrm{.}012$ kg slides down the frictionless loop$-$the$-$loop. The loop has radius R$=12$ cm$.$ The block is initially at rest at point P from height h $=5\mathrm{.}0$R above the bottom of the loop. How much work does the gravitational force do on the block as the block travels from point P to a$.$ bottom of the loop?

b$.$ the top of the loop?

What is the speed of the block at:

c$.$ bottom of the loop?

d$.$ the top of the loop?

What is the normal force on the block at

e$.$ bottom of the loop?

f$.$ the top of the loop?