A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m for 1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up, considering work is done only when the weight is lifted up? Fat supplies 3.8×107 J/kg which is converted to mechanical energy at an efficiency of 20% . Take g=9.8 ms−2. Consider weight to be lifted slowly.