A ball rolls off an 8.0 m high building and strikes the ground 5.0 m away from the base of the building. How fast was the ball rolling?

horizontal speed is 3.9 m/s

Explanation: when ball starts to drop, its vertical speed v0 is zero.

We can calculate dropping time from s = v0t +0.5gt².

Dropping time t= √(2s/g)= √((2·8.0 m)/9.81 m/s²)= 1.277 s

Because ball travels horizontal distance s= 5.0 m

HorizontalSpeed v = s/t = 5.0 m/1.277s= 3,915 m/s

not too sure thinking all accelerations are pointed down

no. bullets are macro objects. wave nature is for light waves, extremely tiny particles. if a light particle was the size of your finger, the bullet would be the size of the universe. so basically, that huge difference in size makes the wave nature of matter insignificant.