## Applying Drag force to a projectile.

Mechanics, discrete, statistics, ...
ImperialDogma
Posts: 1
Joined: Sun Jan 08, 2012 4:30 am

### Applying Drag force to a projectile.

A friend and I have been racking our brain over a problem.

Given an initial height $h$, a final height $h_f$ a set $d$ distance away, and a final angle $\theta$, is it possible to get an initial angle and velocity while including drag force?

We have to deduce a formula mathematically, and couldn't come up with anything. Trying to program something came up fruitless too. An exact answer wouldn't be necessary but a method of getting relatively close values is what we are seeking. Can any of y'all come up with a solution?

Thanks,
ImperialDogma

thundre
Posts: 356
Joined: Sun Mar 27, 2011 9:01 am

### Re: Applying Drag force to a projectile.

The difficulty of this problem depends on how you model the drag.

If you model it as proportional to V3, you get a system of differential equations. You would then apply your known constants as boundary conditions.

An easier problem would be to model drag as proportional to V. That makes the equations for x and y easier to separate, because the x component of the drag depends only on the x component of the velocity and is independent of the y component. 