Determining tractive effort

1. May 13, 2015

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 ive 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?

2. May 13, 2015

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!

3. May 13, 2015

jack action

That's how I would do it.