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Originally Posted by Bizkit 1. The problem statement, all variables and given/known data A 1.5 m 3 tank containing air at 35°C and 750 kPa is connected by a valve to another tank containing 8.25 kg of air at 65°C and 265 kPa. Now the ...

You need to remember that both and are functions of the position vector (and hence , and )....so when you are taking spatial derivatives of the product of either of these functions with say, , you need to use the product rule. For example,

Welcome to Physics Forums! And sorry for the delay in responding. Up until the last 10 minutes, I was not familiar with this type of problem. After a google search, I am now familiar with two ways to solve this problem. One way is the way you did it, but they don't seem to want that. The other way is shown here, look at the equation for Z eff : http://www.physicsforums.com/...

It seems strange to me that AC power consumption changes with the fuel consumption. It seems like it should be relatively constant for a constant setting (unless your car has climate control and you can set the a desired temperature). That is, I would think more fuel would go to keeping the car moving at higher speeds than would go to keeping the inside cool...

Since the question indicates these are hydrogen atoms , it is not considered a diatomic gas in this case. Try looking up Boltzmann Factors in your textbook.

For #1, you can't just assume that whenever . Remember how you compute a matrix element:

For complex amplitudes, one squares the absolute value of the amplitude to get the power response.

"0.8= vb'-va' /2" is wrong. (vb'-va')/4 = 0.8. ehild

I don't know how to do the problem, but I do know that you made a mistake when you multiplied the numerator by the complex conjugate of the denominator. The i's don't go away for the numerator.

Hi SpringPhysics! (have an alpha: α and an omega: ω and a theta: θ and try using the X 2 tag just above the Reply box ) Yes, conservation of mechanical energy should give you θ' 2 + f(θ) = constant … the question says "at small angles", so now replace cos or sin by polynomials, and integrate. (btw, it isn't (R-r)sinθ, it's (R-r)(1-cosθ))

Originally Posted by Doc Al Your problem description is not quite clear. I assume that the problem begins with a ball at rest on a platform (on top of a frictionless surface)? And that you need the minimum coefficient of friction so that ...

never mind.. i just noticed it..

Originally Posted by MathematicalPhysicist 3. I am not sure, but I think I need to expand dV by r>>R0, but after that I don't know how to procceed. Any hints? What is the equation to find ...

For #2 you should start with Schrodinger's equation: And work from there.

I should add that I have absolutely no idea where or how the 1.2kg of nitrogen comes in to the equation, nor if V1 is in fact 1. Please help me i've been staring at this one for hours!

Looks to me like part (c) requires you to develop a differential equation describing the heat transfer. Can you perform an energy balance on a slice of the rod showing the inputs and outputs from conduction and convection?

It's a Gaussian integral that comes out to be

I think your professor is trying to say something like this: If we have because y commutes can just be factored out.

Well, I didn't check your math but it seems that your Hamiltonian does not include the potential energy for the harmonic oscillator. I think you should get something proportional to