# New to calculating automotive formula. Help!

1. May 18, 2010

### Mr Average

1. The problem statement, all variables and given/known data
A vehicle has a mass of X tonne. Tractive effort is Y kN. Travelling on a level road. Formula to calculate acceleration is a=f/m and tractive resistance is 250N (for example). How the devil do I work out the acceleration of the vehicle? I am totally stumped.

2. Relevant equations

3. The attempt at a solution

2. May 18, 2010

### PhanthomJay

It's F_net = ma, not F=ma. If you are given the mass of the vehicle, X, and the tractive effort, Y, and the tractive resistance, R, then a = F_net/X, where F_net is the algebraic sum of Y and R (which act in opposite directions). Don't forget to convert tonnes to kilograms, and be consistent with force units.

3. May 18, 2010

### xxChrisxx

I'm struggling to find a way to walk you through this without giving the answer away.

You just put what you know in newtons second law equation. look at the units of the info you are given, then look at the units used in the equation.

4. May 18, 2010

### Mr Average

Thanks for the offers of help folks.