Question

I believe this is a projectile motion problem with the angle = 0 degrees.

A ball is thrown horizontally from the roof of a building 7.5 m tall and lands 9.5 m from the base. What was the ball's initial speed?

How would I start off this problem? Or set it up throughout?

Answer 1

first drop the ball to see how long it is in the air

7.5 = 4.9 t^2
solve for t

now horizontal problem
u t = 9.5
u = 9.5 / t

Answer 2

Thank you.
May I ask what equation you used for the first one, when solving for t?
I believe my professor uses a different variable.