Projectile motion?

Question

You roll a ball horizontally off the edge of a table. The instant the ball leaves the table its 1.00 m off the floor, and is moving horizontally. It hits the floor after traveling .750m to the right What was its speed as it left the table?

Answer 1

You know the distance it travelled so you need to know the time it took it to do this. This time is of course the time it takes the ball to fall to the floor.

s = (1/2)gt^2 and g = 9.8 m/s^2 is the acceleration of gravity
t = SQRT(2s/g) = SQRT(2(1)/9.8)
t = 0.4518 seconds

Distance = Speed*Time
Speed = Distance/Time
Speed = 0.75/0.4518 m/s
Speed = 1.66 m/s