- #36
stewartcs
Science Advisor
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collinsmark said:Consider this, and it may illustrate the point. Consider a souped up Mazarati and a used 4-cylinder economy car, each climbing the same mountain hill, which is very long and very steep (and constant grade). The Mazarati climbs the hill at 60 mph while the economy car climbs the hill at 20 mph. Assuming both cars have equal mass, and ignoring air resistance and tire friction, both engines are producing the same force on the respective car. The mazarati's force is the same as the economy car's force. But the Mazarati uses more horsepower, so it gets up the hill faster.
Consider that same Mazarati sitting on that same hill. Now consider it sitting still with no motion and using the clutch and engine to maintain its position (not moving up or down the hill). Is energy still being used? Yes. If there wasn't we wouldn't need fuel for our cars.
Is there work being done on the Mazarati? No, because it is not moving.
CS