Calculating Tractive Effort on a Slope: A Case Study

[blaphysics]

I have a question here which involves a car of mass 2100kg going up a slope of 1 in 10, accelerating from 7m/s to 11m/s, through a distance 145m. There is also frictional resistance of 1.7kn. Essentially I would like someone to run through what I've done and offer any assistance if possible, which would be great (Ive tried to keep this short):

One of the questions in this scenario is to work out the tractive effort between the wheels and the slope:

• Firstly I worked out acceleration via (change in speed/ 2 x (distance)) to get 0.24828m/s^2.

• I worked out inertia resistance (ma), by multiplying the 2100kg by the acceleration, to get 521.38N

• Did tan^-1(0.1) to calculate the angle of the slope as 5.71 degrees

• Determine gravitational resistance using mgsin(angle), so 2100 x 9.81 x Sin5.71 = 2049.7N

Would I be correct in assuming that the overall tractive effort is 2049.7 + 521.38 + 1700 = 4271.04N, or am I doing something wrong here, this would essentially mean the tractive effort is the sum of everything resisting the vehicle?

 

[blaphysics]

Also, calculating work done during the acceleration:

This is force x distance, however would the force I use be the force determined previously (the tractive effort)?

Thank you for any help!

 

[jack action]

That's how I would do it.