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Old 11-14-2012, 05:42 AM   #22 (permalink)
serialk11r
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Quote:
Originally Posted by redpoint5 View Post
Your basic physics are incorrect. Without a force counteracting gravity, a vehicle will roll downhill. That force is provided by the engine and can be tested by stopping on a steep hill in an automatic transmission car. It takes some amount of energy to prevent the car from rolling downhill when the brakes are released. It takes yet more energy to produce forward movement.
No, it takes no energy to keep a car on a hill. Energy is force * displacement or distance (well, more precisely it's the integral of the cross product of the force and displacement vectors). Hint, brakes don't use energy.
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