Recent content by thinkingcap81

Hi Dale, Thanks for your informative reply which answers the last part of post #3 in this thread. I'm still going to continue asking you and others though. Let us have a simple adiabatic piston-cylinder arrangement with the cylinder moving at a constant velocity ##V##. Let a RF be attached to...

You need to decide what is your system - just the mass ##m##, or the mass ##m## and the spring. Try deriving the following: ##mgh = \frac{1}{2}mV^2## where ##V## is the velocity of ##m## at the moment of impact with the spring. ##mgh + mgx = \frac{1}{2}kx^2## Use the principle of conservation of...

Hi CM, I meant that the fuel releases energy which gets transferred to the mass ##m## across a boundary. So can we take this energy transfer as ##Q##? The chemical composition of the fuel changes which i think is identically measured in both moving and stationary RFs. You could ask for more...

Hi CK, Thanks for your reply. I am aware of this. I do not dispute the ##\Delta{}KE## differences in stationary and moving RFs. However the energy, ##Q##, expended by burning a fuel is measured identically in both RFs (else are we measuring incorrect energy content of fuels on the Earth?). So...

I'd like to apply the 1st law of thermodynamics in a reference frame (RF) moving with constant velocity. We have: ##\Delta{}E = E_{in} - E_{out}## I am limiting myself to rectilinear motion. Suppose we are in a RF moving with a constant velocity ##V##. Let the system consist of a mass ##m##. The...

Ah! Thanks about the insight about probabilities. It did cross my mind that the more energized particle will frequent the same region more number of times, but i didn't think of the math. I think that you kept the volume ##V## fixed for a gas, but of course, not for a solid. Now let's say that...

If i knew how to precisely and explicitly explain randomness then it would be a lot better for me. Let me just say that to me it means, in a crude sense, how particles can be located in a region of space. GAS: Identify a region of space containing some amount of a gas. A particle spends a...

I think that there's some miscommunication between us. I know that randomness is a measure of entropy. I am hoping for an equation that says ##\text{this much change in randomness gives rise to this much change in entropy}##

Yes, i do, in an intuitive sense. I cannot precisely explain it.

Hypothetical reversible heat transfer at infinitesimal temperature difference. I just wanted to make the comparison between the solid and gas/liquid as simple as possible, and so kept the same heat capacity and temperatures.

I know that you know what entropy is. I was asking for an equation defining entropy in terms of randomness. Or you can offer me a better explanation from the statistical POV in place of the classical equation in your reply. Thanks.

Hi Dale, I know that the entropy change is same for both cases, but am unable to explain it in terms of randomness. How do we quantify randomness of a solid since the molecules have a well defined structure and do not shift from their positions except for vibrations about their mean position...

Hi Dale, I know the equation that you have mentioned. I am seeking clarity with respect to the oft repeated explanations of entropy increase with regard to the increase in randomness of the molecules/atoms of matter. If the same amount of heat is transferred to a solid and gas/liquid at the...

A hypothetical question. Heat Q is transferred from water to a metallic solid. Both have same heat capacities and the same initial temperature. Now since molecules in a liquid are more randomly oriented than a solid, will the entropy decrease of the liquid be more than the entropy increase of...

I'm trying to solve a problem where a perfect ideal gas is entering an initially evacuated rigid vessel. The input pressure and temperature are Pi and Ti which are constant. The incoming mass Mi is an arbitrary function of time. When i solve this, i get the temperature inside the container as...