# Search results

1. ### Independence of Energy and Momentum Conservation

Suppose we take the three Newton’s Laws as axioms. Existence of inertial reference frames F = ma F(A on B) = -F(B on A) Also suppose also we are considering purely classical mechanical processes on point particles (no heat transfer, etc.). It is clear to me that the conservation of momentum...
2. ### Physical interpretation of divergence

I'm trying to figure out what the physical meaning of divergence is for a vector field. My textbook offered the following example: if v = <u, v, w> represents the velocity field of a fluid flow, then div(v) evaluated at P = (x, y, z) represents the net rate of the change of mass of the fluid...
3. ### Entropy change with elevation

I have seen in a number of thermodynamics lectures that the entropy change of a system as it falls approximately isothermally from some height h to the ground is: ΔS = mgh/T (The proof basically has you conceive of a reversible process between the same two states where some upwards force acts...
4. ### Change in Entropy for Irreversible Processes

I was following along in my Thermodynamic textbook and began playing with some definitions. In the following formulation, I somehow managed to prove (obviously incorrectly) that dq = TdS for even irreversible processes. I was hoping someone could point out where in the proof I'm going wrong...
5. ### Work done by gravitational force

This is a purely conceptual question that I’m having trouble understanding. From what I understand, anytime an energy transfer takes place as work, you can say that something has done work on something else. For example, if the gas in a cylinder with a piston on it pushes back the atmosphere...
6. ### Is there such a thing as a total partial derivative?

Is there such a thing as a total "partial" derivative? Total Derivative as I've Been Taught From my understanding, if we have a function s = f(x, y) where the two arguments x and y are related by another function y = g(x), then there is a great deal of difference between ds/dx and ∂s/∂x. ∂s/∂x...
7. ### Volume Injected into Capillary

Homework Statement So for an experiment, we injected a small volume of fluid into a capillary (76 micrometer diameter) through a pressure difference and I'm trying to calculate exactly how much was injected. diameter of capillary = 76e-6 m height one end was raised above the other = 5.334 cm...