# Free-fall kinematics on a plane: Displacement from Window to Ground?

1. Oct 14, 2012

### Veras

1. The problem statement, all variables and given/known data
A ball is thrown vertically upward from a window at 10m/s. It hits the ground 5.0 seconds later. What is the height of the window from the ground?

Given
Vi = 10 m/s
Vf = 0
Δt = 5.0 m/s
$$Δa = -9.8 m/s^2$$

Find
Δd(w-g) = ?

2. Relevant equations

Δd = Vi(Δt) + $Δa(Δt)^2$

And the other four "kinematic equations"

3. The attempt at a solution

Total displacement:

$$Δd = ((vi + vf)/2)(Δt)$$

= (10/2)(5)
= 25 m

Not sure where to go from here and if I'm on the right track. Your help is greatly appreciated!

P.S. I apologize for the terrible formatting. I'll get it soon enough!

2. Oct 14, 2012

### Veras

Question has been resolved outside of the forum. Admin, feel free to delete this thread.