Calculating Work, Heat & Energy Change in Gas

AI Thread Summary
The discussion revolves around understanding the term "change in the energy content of the gas" in the context of a homework problem involving work and heat. Participants clarify that "energy content" refers to internal energy, and the first law of thermodynamics is relevant to this concept. The equation ΔU = Q + W is confirmed as the correct approach to calculate the change in internal energy. The conversation emphasizes the relationship between heat added, work done, and the resulting change in energy content. This understanding is crucial for solving the problem accurately.
jason177
Messages
24
Reaction score
0

Homework Statement


I don't need help on the problem itself but I did have a question about what does this mean by change in the energy content of the gas?
The question is:
For each of the four steps A through D, compute the work done on the gas, the heat added to the gas, and the change in the energy content of the gas.

and then there is a P vs V graph that we are supposed to use to answer the question.

The Attempt at a Solution


I thought it might mean what percent of the change in energy is caused by heat and what percent is caused by work but I'm not sure and it doesn't say anything about it in the book.
 
Last edited:
Physics news on Phys.org
anyone have any ideas?
 
By "energy content" they mean internal energy. What does the first law of thermodynamics have to say about that?
 
ok, so for change in energy content I would basically just use \DeltaU = Q+W ?
 
jason177 said:
ok, so for change in energy content I would basically just use \DeltaU = Q+W ?
Exactly.
 
Alright, thank you very much for the help
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top