A plane is traveling at an altitude of 500meters and drops a bottle the bottle lands 400meters horizontally. how fast was the plane traveling when the bottle was released?

Answer 1

The bottle and the plane travel the same horizontal speed and distance

How long to fall 500 m?
500 = (1/2) 9.8 t^2
solve for t

How far in t seconds?
400 = v t
so
v = 400 / t