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# Important for physicist watch

1. Explain why the first law in thermodynamics is a consequence of the law of conservation of energy
2. why is the energy needed to raise the temperature of a fixed mass of gas by specific amount is greater if the pressure is kept constant than if the volume is kept constant?
3. Pure speculation here on the second one but I would assume it's based on volume being a cubed unit? Someone correct me on this please?
Explain why the first law in thermodynamics is a consequence of the law of conservation of energy
U = Q - W indicates that the total internal energy of the system is the sum of the heat added and the work done on/by the system -- internal energy can be transformed into heat energy or work, but is not created or destroyed, as shown with internal energy as the sum.
why is the energy needed to raise the temperature of a fixed mass of gas by specific amount is greater if the pressure is kept constant than if the volume is kept constant?
If the volume is kept constant, it's called an isochoric process. In isochoric processes, no work is done. In constant pressure (isobaric) processes, work is done through a change in volume. If the temperature is increased by the same amount for both processes, they both have the same increase in internal energy. However, because additional external work is done by an isobaric process, it takes more energy to raise the temperature of an isobaric, constant-pressure process than one with constant volume.

I hope this helps
5. (Original post by Regulus)
U = Q - W indicates that the total internal energy of the system is the sum of the heat added and the work done on/by the system -- internal energy can be transformed into heat energy or work, but is not created or destroyed, as shown with internal energy as the sum.If the volume is kept constant, it's called an isochoric process. In isochoric processes, no work is done. In constant pressure (isobaric) processes, work is done through a change in volume. If the temperature is increased by the same amount for both processes, they both have the same increase in internal energy. However, because additional external work is done by an isobaric process, it takes more energy to raise the temperature of an isobaric, constant-pressure process than one with constant volume.

I hope this helps
thank you ...I go it

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