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Question
Explain the different ways through which the internal energy of the system can be changed.
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Solution
- The internal energy of a system can be changed by changing the temperature of the system:
a. If the system is placed in an environment that is at a temperature lower than the system, i.e., TS > TE, the energy is transferred from the system to the environment causing a decrease in the internal energy of the system.
b. If the system is placed in an environment that is at a temperature higher than the system, i.e., TE > TS, the energy is transferred from the environment to the system causing the increase in the internal energy of the system. - The internal energy of a system can be changed by doing some work:
a. When some work is done on the system by the environment, the system gains energy, and its temperature increases causing an increase in internal energy.
b. When some work is done by the system on the environment, the system loses the energy, and its temperature decreases causing a decrease in internal energy.
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