a friend of mine asked if i could help him work out some equations for a (fairly) long range projectile, to go no farther than 2 miles or so. i have everything reasonably worked out except for acceleration due to air resistance. i'm using the equation from https://www.physicsforums.com/showthread.php?t=9066" thread to calculade Fd, and Cd=.295, rho=1.22752kg/m^3, A=pi.2^2m^2, v=240m/s, firing an object with a mass of .23kg. (Cd and rho both came from the Nasa website) I did the calculations and got an estimated acceleration of about (-)5698 m/s^2, which obviously cannot be right.(adsbygoogle = window.adsbygoogle || []).push({});

I was also wondering if there is any way to get a more accurate velocity by factoring in acceleration of gravity and air resistance. I'd assume it'll take some nasty algebra/calculus, but i can't figure it out on my own.

any help is greatly appreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Acceleration due to air resistance?

**Physics Forums | Science Articles, Homework Help, Discussion**