Thermal Expansion for an Ideal Gas

AI Thread Summary
The relationship between pressure, volume, number of moles, and temperature for an ideal gas is described by the equation pv=nRT. To prove that the coefficient of volume expansion at constant pressure is the reciprocal of the Kelvin temperature, one must calculate the coefficient using the formula α_V = (1/V)(∂V/∂T)_p. By substituting V(T) = nRT/p into this equation, the inverse temperature dependence can be demonstrated. Additionally, the discussion compares the coefficients of volume expansion for copper and air at 20°C, treating air as an ideal gas under constant pressure. This analysis highlights the unique thermal expansion characteristics of gases compared to solids.
ryaneye
Messages
5
Reaction score
0

Homework Statement



The pressure p , volume V, number of moles n, and Kelvin temperature K of an ideal gas are related by the equation pv=nRT , where R is a constant. Prove that the coefficient of volume expansion for an ideal gas is equal to the reciprocal of the Kelvin temperature if the expansion occurs at constant pressure.

Homework Equations


Compare the coefficients of volume expansion of copper and air at a temperature of 20 C. Assume that air may be treated as an ideal gas and that the pressure remains constant.


The Attempt at a Solution


?
 
Physics news on Phys.org
The coefficient of thermal expansion at constant pressure is given by
$$\alpha_V=\frac{1}{V}\left(\frac{\partial V}{\partial T}\right)_p$$
By calculating this quantity for ##V(T)=\frac{nRT}{p}##, you can show an inverse temperature dependence.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top