A ball is projected horizontally from the top of a bertical building 25.0m above the ground level with an initial velocity of 8.25m/s . Calculate : a. How long is the ball in flight before striking the ground
b. How far from the building does the ball strike the ground

Solution given:

height [H]=25m

initial velocity [u]=8.25m/s

g=9.8m/s

now;

a. How long is the ball in flight before striking the ground?

Time of flight =?

Now

Time of flight=

substituting value

b. How far from the building does the ball strike the ground?

Horizontal range=?

we have

Horizontal range=u*

it is a negative acceleration