Specific Heats for Incompressible Fluids

AI Thread Summary
The discussion centers on the relationship between specific heats for incompressible fluids, specifically addressing the equation Cp = Cv + R. It highlights a contradiction where the book states Cp equals Cv for incompressible fluids, despite R being a constant. Participants express confusion over how R can be zero for incompressible fluids and seek clarification on determining specific heat values. The consensus suggests that specific heat values are typically provided in problem statements or reference tables. Understanding this relationship is crucial for solving related thermodynamic problems.
Spectre5
Messages
182
Reaction score
0
Given the following equation:

Cp = Cv + R

Where Cp is specific heat (constant pressure), Cv is specific heat (constant volume), and R is the universal gas constant.

However, my book states that for an incompressible fluid, Cp = Cv.

How can this be the case given the above equation? R is a constant for any given fluid, so why is is zero for an incompressible fluid?
 
Physics news on Phys.org
Nevermind, I think I figured it out
 
Can you explain to me what you figured out then (or someone)?
I don't understand how the specific heat for an ICL is supposed to be determined.
 
Elbobo said:
Can you explain to me what you figured out then (or someone)?
I don't understand how the specific heat for an ICL is supposed to be determined.
The specific heat is usually provided for you in the problem statement, or in a table somewhere in the textbook.
 
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