Write the speed of the ball at the top of the window as
and at the bottom of the window
Call the time between when the ball is at the top of the window and at the bottom of the window
So we know
These speeds are related:
The average speed is
The distance traveled in the time
We can solve this for
Now that we know
we can find the height of the building above the top of the window.
The time that the object has fallen to get to the top of the window
The total time for falling is then
Note that we had to divide the last time by two!
The total distance from the top of the building to the bottom is then