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A person trying to lose weight (dieter) ...

A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a height of 0.5m each time. Assume that the potential energy lost each time she lowers the mass is dissipated.
Fat supplies `3.8xx10^(7) J` of energy per kilogram which is converted to mechanical energy with a 20% efficiency rate. How much fat will the dieter use up?

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`= 6.45 xx 10^(-3)kg`
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