Question

A ball thrown vertically upwards is caught by the thrower 8 seconds afterwards . (take g =10) When the ball is caught by the thrower: what is its displacement from the initial position?
b) what is the initial velocity?
c) To what height does the ball rise?
d) With regard to (c) at the greatest height reached, what is the velocity of the ball?

Answer 1

a. displacement = 0, it is at the same position as when it started.
b. df=di+vi*t-1/2 g t^2
df=di=0 solve for vi. I have no idea why you were told to use g=10, it is not that value anywhere on Earth. Nor is PI equal to 3

c. at the top, velocity is zero, so vf=0=vi-gt hwere t=4sec, and vi equal to what you found in b.