Science Buddies: "Ask an Expert"

I have completed the experiment of measuring velocity of a paintball.
I added a horizontal trial where I shot the paintball parallel to the earth, zero degrees. I am unsure what velocity equation to use as the 90 deg and 45 deg velocity equations changed.
90 deg: V=1/2gt
45 deg: V=.71gt
Any help with 0 deg equation would be appreciated.

Hello mpkscience,

All the formulas assume that the paintball is fired from ground level. If the gun is fired horizontally at ground level, then the paintball is on the ground as soon as it leaves the barrel.

If you want to fire the paintball horizontally at some height, say H, then the time to hit the ground and distance traveled before hitting the ground is as follows.

Time to hit the ground is determined by H = 1/2 gt^2 (t squared).

Distance traveled D = Vt.

Combining the equations gives t = sqrt(2 H/g) and D = V sqrt(2H/g). (Be sure to check my algebra!).

Good luck, WW

Thank you WW. I knew I was missing something in my thought process....it was the height from the ground

MPK