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unusual mechanics question please help

A car of mass 1500 kg is running on a level road at 48 kmh-1. It is then allowed to freewheel (no engine power) down a gradient of 1 in 20 where the speed is the same as before. Determine the resistance of the road and the power exerted on the level.

I dont understand how to work with the 1 in 20 gradient is that 1/20% please help

Reply 1

Flauta

Original post by Dontay

1/20 gradient is an angle of

\arctan(\frac{1}{20})

between the horizontal and the slope, you're going down 1 for every 20 you go along, y=1 x=20. Can then use that angle to find the component of the car's weight parallel to the slope.