distance question

[LTLGRMLN]

ok, I wanted to know, since it seems like you guys know physics well... how far a 3 gram paintball 3 feet off the ground going at 250fps would go. This is w/o friction and the gun is at a perfectly level angle... a formula is fine too. any help?

[SLICEnDICE]

A start

Look up a projetile motion formula. That will be a good start.

[LTLGRMLN]

thanks

[classicmagplayer]

find how long it would take for the ball to drop 3 feet: 3*30.5/100=.915meters
.915meters=V0+1/2AT^2....
.915meters=0+ 1/2*9.8*T^2
T=.432 seconds

then multiply the time by the horizontal velocity....250f/s
250*.432=108 feet

dont need projectile motion until you angle the 'gun, it would be nice to see air resistance factored in, but I havent learned that yet

[Troy90j]

You can't really factor in air resistance very easily. Well I guess it's not that hard, but requires the use of differential equations which are not very common knowledge.

[bjjb99]

I would want to use differential equations if I were looking for a closed form symbolic solution (i.e. plug in the numbers and an answer just pops out) to projectile motion with air resistance. You can get arbitrarily close using numerical methods, basic algebra, an understanding of the forces involved, and a decent spreadsheet application. Just use small enough time increments between successive calculations and you're all set to leave some of the diff. eq. stuff behind.

BJJB

[Troy90j]

Yeah well I like to use my calculus, guess that's why I'm a Math/Physics major and not an Engineer. Exact answers may be near impossible to get, but it's fun to play around with the math anyway. (Yes, math is FUN..remember that kids )

[Wat]

Troy

If you think Math/Physics are all about exact answers and only require calculus, you've got a long way to go. Just about everything interesting is a non linear equation with no exact solution. The reason air resistance can't me modeled exactly is because the underlying physics that governs fluids, the Navier-Stokes Equation, is non linear and competely unsolvable. As for the rest of physics, Hisenberg's uncertainty principle means that nothing is ever known exactly. Quantum Mechanics and electron clouds are all just probabilities as well.

There's nothing at all imprecise about engineering. Its merely taking an understanding of physics and using it to solve problems under real world constraints.

[Troy90j]

Yeah I just like to poke fun at the engineers whenever I get a chance. It's all in good fun though, without them our ideas would just remain as ideas.

[Dueydog]

Here's a site that proves range with three different markers!

http://www.pbstar.com/misc-tech/range-debate/

http://www.pbstar.com/high-tech-semi-review/

Here you go. Tons of info on everything. And check out the reviews on EMag, Dark Angel and Cocker. The EMag was more accurate and consistant. How's that for killing myths!
Thanks,
Matt

[FallNAngel]

Perhaps I'm a bit lost, but I don't see anywhere where it says the emag was more accurate or more consistant than a Dark Angel or an Autococker. If you're basing it just off of what they said in each of the reviews, then you may want to read the Autococker review again. They said at the end after shooting about 1.5 cases of paint or so through the marker that it shot more consistant, though they didn't post those numbers.