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Work Power and Energy question

2016 · Shift 0 · Q61
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Work Power and Energy question

2016 · Shift 0 · Q61

JEE MainPhysicsWork Power and EnergyMCQ+4 / −1
A person trying to lose weight by burning fat lifts a mass of 10kg10kg10kg upto a height of 1m10001m10001m1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work done only when the weight is lifted up? Fat supplies 3.8×107J3.8 \times {10^7}J3.8×107J of energy per kgkgkg which is converted to mechanical energy with a 20%20\%20% efficiency rate. Take g=9.8 ms−2g = 9.8\,m{s^{ - 2}}g=9.8ms−2 :
  1. A
    9.89×10−3  kg9.89 \times {10^{ - 3}}\,\,kg9.89×10−3kg
  2. B
    12.89×10−3 kg12.89 \times {10^{ - 3}}\,kg12.89×10−3kg
  3. C
    2.45×10−3  kg2.45 \times {10^{ - 3}}\,\,kg2.45×10−3kg
  4. D
    6.45×10−3  kg6.45 \times {10^{ - 3}}\,\,kg6.45×10−3kg
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