1. A gas expands and does p-v work on the surroundings equal to 279j. At the same time it absorbs, 216j of heat from the surroundings. What
is the change in energy of the system?

Please answer if yk

The change in energy of the system : -63 J

Given

279 J work

216 J heat

Required

The change in energy

Solution

Laws of thermodynamics 1

ΔU=Q+W

Rules :

a gas work on the surrounding : W =-279 J

a gas absorb heat from surrounding : Q = +216 J

Internal energy :

= -279+216

= -63 J

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as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.