I have spent the whole day trying to figure out the equations having to do with drag on objects with a fixed mass.

My example which I included is kinda like a classic cannon shooting example(Platform-scrolling).

I have figured out how to implement gravity and convert it to pixels.

(1 meter = 32 pixels)

My problem is drag, and how to implement it.

I found this:

http://www.grc.nasa.gov/WWW/k-12/airplane/flteqs.html

(alot of interesting articles)

This is the formula:

D = .5 * Cd * r * A * Vt^2

D = Drag (Fd)

Cd = Drag Coefficient (Bullet = 0.295)

r(rho) = Gas Density (Air at sea level = 1.225 kg/m3)

A = Cross-sectional area (Circles; A = Pi * r^2)

Vt = Terminal Velocity (m/s^2)

When I calculate this I get a value, I think is is N(Newtons).

Since I am a greeny on physics I almost have no idea of what I am doing.

Please be gentle.

So how would I go about inplementing this to the Xpos and Ypos on the bullet. Which updates every 10 milliseconds. (In my example below)

Any help is very very appriciated!

Please explain like I was a 5 year old.

According to this:

http://en.wikipedia.org/wiki/External_ballistics

*Drag or the air resistance decelerates the projectile with a force proportional to the square of the velocity.*

Im not sure about this...

Here is my file:

http://web.comhem.se/~u54025770/ballistic_test.rar

/MJOne