Calculate the exit force of a bullet leaving the barrel

[JJ_Badoo]

TL;DR

Hello, I am doing a project in which I have a bullet and it is being fired from a barrel.

So, Basic premise is I have 1 input and one output, Energy friom the gunpower burning is input, and the output is the force which pushes the bullet after it is reduced by the friction.

m = 12.96 g
s = 0.6985 m (barrel lenght)
E = 6734 J
k = 0.5 (friction coeffcient)

I am sorry for lack of anything really. I don't even know how to start, I could solve the exercise normally but them shifting it over to MATLAB parameters is the most difficult thing for me...
Thank you.

https://www.physicsforums.com/attachments/245431

 

[BvU]

Hello JJ, $\qquad$ $\qquad$ !

For the friction force you write $-kx$. Where does that come from ? What would it mean for the energy lost to friction ?

I am sorry for lack of anything really. I don't even know how to start

Not good enough for PF -- see guidelines

I could solve the exercise normally

Please do solve, and post what you have, including thte relevant equations ...

 

[jrmichler]

I don't even know how to start

Do some reading on interior ballistics. Hatcher's Notebook, by Julian S. Hatcher, has some good information on the energy budget, including friction.