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A certain electric motor produced `16kJ` of energy each second as mechanical work and lost `3kJ` as heat to the surroundings. What is the change in the internal energy of the motor and its power supply each second? |
Answer» Energy is lost form the system as work, thus `W` is negative. `:. W =- 16kJ` Enegry is lost as heat, so `q =- 3kJ` Therefore, by the first law of thermodnamics, `DeltaU = q +w =- 3 - 16 - 19kJ` |
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