View Single Post
Old November 3rd, 2008, 22:36   #19
mcguyver's Avatar
Join Date: Aug 2005
Location: Northern Alberta
Originally Posted by Skladfin View Post
that's a really dumb theory you have there, 20% decrease in mass doesn't mean 20% increase in velocity.

things don't work like that, it always have to follow a formula. We'll keep it simple, you can find the difference in velocity between 0.20g and 0.25g using 2 physics formulas

F= ma
vf(squared) = vi(squared) + 2ad

F = force applied
m = mass
a = acceleration
vf = Final velocity when leaving the barrel
vi = initial velocity before force being applied(so in this case, zero)
d = distance traveled between vi to vf

did some calculations and here are the results(In the calculation, I'm assuming that it fires 400FPS with 0.25g)
I also neglect any friction force between barrel and BB during barrel travel, and hop up effect.

From my chrono results(and yours too) shows that the difference in velocity between 0.20 and 0.25g IS roughly 40FPS give or take a few FPS (because of hop up/friction).

so no, 20% mass decrease in mass does NOT equal 20% increase in velocity.
I know this. I was using the % as a measure of change, not an actual "to be expected" result. Re-read my post again.
Age verifier Northern Alberta

Democracy is two wolves and a sheep discussing what's for dinner.

Freedom is the wolves limping away while the sheep reloads.

Never confuse freedom with democracy.
mcguyver is offline   Reply With Quote