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If you assume that the fluid is incompressible, I'm relatively sure that it could be shown that 100% efficiency is theoretically possible. You could use a variety of mental models to do this. I would prefer to think about conventional hydraulics lifting some weight. If you match the weight to the pressure, then you could raise an external object some (m g h) ...

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Turbines (impellers) have fins that work more like aircraft wings and sails than the buckets of a old water wheel. They have have very high lift/drag ratios which translate the high efficiency. It is friction and heat loss that kill efficiency not the work of the turbine (how much it spins).

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Short answer is: If you heat up the whole material, then no. If you heat up the material in on end (an iron bar e.g.), then yes. The thermoelectric effect will cause a small current to flow between the two ends of different temperature. It looks like you are mistakenly assuming that electromagnetic induction causes heating, which should then be possible ...

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in this situation a normal man will have less weight than horse and car so it clearly states that acceleration must be same. No. If the force is the same for all 3, then if the mass is different, the acceleration must be different. Since the man has the least mass, then he will accelerate the fastest. So the man would win the race. But in the real ...

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Let's work through this problem... $$\text{Power} = \frac{\text{Work}}{\text{Time}} \; \text{and} \; \text{Work} = \text{Force}\cdot \text{Displacement}$$ therefore $$\text{Power} = \frac{\text{Force}\cdot\text{Displacement}}{\text{Time}}$$ From Newton's Second law we know $$\text{Force} = \text{Mass}\cdot\text{Acceleration}$$ Substituting again: ...

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No, you cant. Because it is simple to know mpg we have to calculate fuel flow. Only measuring speed and acceleration you know variation distance time and need to calculate fuel flow also.

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a watt is one joule of energy per second. A given Wind turbine produces more energy per second (more watts) when it is rotating faster. Power of a wind turbine is proportional to the cube of the wind speed.

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