A ball is tied to the end of a cable of negligible mass. The ball is spun in a circle

This problem can be divided in to 2 parts

First part in which stone moves up and second part in which stone moves down.

Let the time for travel in upper direction be and time for travel in down direction be

We have v = u+at, where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken.

  Up direction

               0 = 10 - 9.81*

                = 1.02 seconds

We also have , s is the distance traveled.

                             s = 10*1.02-

Now considering the downward motion.

                  displacement = 5.09+65=70.09 m

a) So total time taken = 3.78+1.02 = 4.8 seconds

b) In case of downward motion v = u+at

          u=0, a = g, t = 3.78 seconds

  So, Velocity on reaching ground = 0+9.81*3.78 = 37.08 m/s

c) Total distance traveled = 5.09+70.09 = 75.18 m

d)Total displacement is height of cliff, which is equal to 65 m