What Are the Equations for Power and Tractive Effort in a Car Ascending a Slope?

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The discussion focuses on calculating the power and tractive effort of a car ascending a slope using D'Alembert's principle. A specific example is provided where a car with a mass of 800 kg accelerates to 50 km/h over 10 seconds on a 1 in 70 incline, facing a rolling resistance of 150 N. The calculated power at 30 km/h is 11.4 kW, while the tractive effort remains unresolved. Key calculations involve determining acceleration and distance traveled, which are 1.389 m/s² and 13.89 m, respectively.

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Hi
I need a bit of help with D'Alembert's principle, I'm after the equations to find the power in a car ascending a slope with fritional resistance. The example I will give is not my assignment question as I want to work that out for myself, but an example from a textbook that just gives me the answers and not the equations, but I cannot find a way using KE and PE to get it right.

A car of mass 800kg accelerates from rest to a speed of 50km/h in 10 seconds, while ascending an incline of 1 in 70. The rolling resistance is 150N. Assuming uniform acceleration, what is

1 the power developed at 30 km/h and
2 the tractive effort

Answer to number 1 is 11.4KW, number 2 is another baffling question I’m afraid.

I have worked out that the acceleration is 1.389m/s and the distance traveled is 13.89

Any help gratefully received
 
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Welcome to PF mitch,

Power is simply the rate at which work is done. Therefore, if one could find the work done then calculation of the power would be trivial.
 
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