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## Main Question or Discussion Point

Hi -

Question: A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a

height of 0.5 m each time. Assume that the potential energy lost each time she

lowers the mass is dissipated. (a) How much work does she do against the gravitational

force ? (b) Fat supplies 3.8 × 107J of energy per kilogram which is converted to

mechanical energy with a 20% efficiency rate. How much fat will the dieter use up?

What is the significance of the following line in this question?

Thanks

Puneet

Question: A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a

height of 0.5 m each time. Assume that the potential energy lost each time she

lowers the mass is dissipated. (a) How much work does she do against the gravitational

force ? (b) Fat supplies 3.8 × 107J of energy per kilogram which is converted to

mechanical energy with a 20% efficiency rate. How much fat will the dieter use up?

What is the significance of the following line in this question?

__"Assume that the potential energy lost each time she lowers the mass is dissipated."__Thanks

Puneet