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I recently have bought an airsoft pistol that shoots 302fps and I thought it would be fun to calculate the max distance & stuff for the bb including air resistance. The problem is including air resistance into the equation.

Here's the stats:

mass of bb= .12g

diameter of bb= 6mm (.006m)

muzzle velocity for .12g bb = 302fps (92.0496m/s)

After reading stuff on the net, I aparently need the equation D=(pCA)/2, where p is the density of air (about 1.2101 kg/m^{3}), C is drag coefficient (around .47 probably?), and A is the area of the bb looking at front (pi*r^{2}= pi*(.003m)^{2}= 2.8274*10^{-5}m^{2})

When I plug the numbers in, D= 8.04046*10^{-6}

I'm sort of lost after this step, aparently Acceleration=-DV^{2}--> A_{x}=-DV(V_{x}) and A_{y}=-DV(V_{y})

I tried plugging the numbers in but the answer was only somewhere around .04 which I'm pretty sure isn't right at all.

My main goal is to put it into a parametric function so I can see it visually with distance and time:

SO, what I'm sure is right (without air resistance):

X_{1T}=92.0496cos(35)

Y_{1T}=92.0496sin(35)-(1/2)9.8T^{2}

What is the air resistance acceleration and how do I plug it into that equation???

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# Homework Help: Help with Projectile Motion problem (including air friction)

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