Question

A football is kicked vertically upward from the ground and a student gazing out of the window sees it moving upward past her at velocity U. The window is a height h above the ground. You may ignore air resistance. How high does the football go above ground?

Answer 1

`H = (u^2)/(2g) + h`

Step-by-step explanation:

Let the football is kicked up vertically with some speed given as

`v = v_o`

now its speed when it will reach to height "h" above the ground is given as "u"

so we will have

`v_f^2 - v_i^2 = 2 a d`

here we have

`u^2 - v_o^2 = 2(-g)h`

so we have

`v_o^2 = u^2 + 2gh`

now we know that when football will reach to maximum height then it will have zero final velocity

So we will have

`v_f^2 - v_i^2 = 2 a s`

`0 - (u^2 + 2gh) = 2(-g)H`

so we have maximum height given as

`H = (u^2 + 2gh)/(2g)`

`H = (u^2)/(2g) + h`