Physics
posted by Haze .
You throw a ball straight down from an apartment balcony to the ground below. The ball has an initial velocity of 5.20 m/s, directed downward, and it hits the ground 2.10 s after it is released. Find the height of the balcony.

Y = H 5.2t 4.9t^2
is the height above ground at time t.
It hits the ground (Y=0) when t = 2.1 s.
Let Y = 0 and t = 2.10 and solve for H