Intro to Projectile Motion: Horizontal Launch Practice Problems

A playground is located 3.5 m from the base of a cliff. This 3.5 m wide zone from the cliff's base is used by cheering spectators. A player at the top of the cliff launches a 4.50 N ball horizontally. What must be the minimum speed of the ball as it leaves the top of the cliff so that it misses the spectator area at the base of the cliff? The spectator area is 3.5 m wide and 12.0 m below the top of the cliff. 

You are having fun in a storey building. You drop a stone downward from the window and notice it reaches the ground in 3.2 s. You now launch a ball horizontally with an initial speed of 1.9 m/s. Ignoring air resistance, at what length, measured from the base of the storey does the ball hit the ground?

You place a metallic sphere on a horizontal board. You accidentally hit the sphere, where it rolls off the board with a speed of 2.5 m/s. It hits the floor in 0.582 s. Calculate the height of the board measured above the floor. Ignore air resistance.