Physics
posted by Robert .
Harry and Hermione look from their balcony to a swimming pool below that is 12.0 m from the bottom of their building. They estimate the balcony is 30.0 m high and wonder how fast they would have to jump horizontally to succeed in reaching the pool. What is your answer? Enter m/s as unit and round g = 10 m/s2.

a. h = Vo*t + 0.5g*t^2 = 30 m.
0 + 5t^2 = 30
t^2 = 6
t = 2.45 s. = Fall time or time in air.
d = V*t = 12 m.
V*2.45 = 12
V = 4.9 m/s.