Recent content by Uku

Homework Statement I am given a Lagrangian, which, per assignment text, describes a single degree of freedom: L= \frac{I}{2}(\dot{q}+\omega)^2-kq^2 I need to find the Hamiltonian. Now, what I am wondering, when performing the Legrende transform...

Hello! The picture says a thousand words: http://www.hot.ee/jaaniussikesed/v6rrand.jpg In the last member under the square root, there is the error. For some reason I am not able to differentiate with an array index, ts1 is a single column 5 row matrix. How to solve this? The error says...

HallsofIvy nailed it, thanks! U.

Hello! I have this thermodynamical expression: dS=\sigma T^3 dV+4V\sigma T^2 dT+\frac{1}{3}\sigma T^3 dV=d(\frac{4}{3}\sigma T^3 V) Basically saying: \frac{4}{3}\sigma T^3 V=S Now, I do not get this.. d(expr) part, why are there three members to d(expr), with 2x dV and 1x dT.. nope...

I messed up on R, since I wrote R=8.314*10^{-3}\frac{kJ}{K} when trying to write R in terms of kJ.

0.012 m3

Well the pressure differential is 0.4 MPa..

By "could have" you mean you put in the numbers and got a different answer?

Homework Statement I have hydrogen in a 12 L tank, at T=15 C. Some of it is used, the T = const. and Δp=0.4 MPa, the molar mass of hydrogen is M=2*10^-3 J/(mol*K). Find the mass of the used hydrogen. Homework Equations Am I wrong in simply using: \Delta m=\frac{M}{RT}V\Delta p ...

Okay, that is true, thank you. I now read from his example that the set is given by default. Still: how would you arrive at y_{1} and y_{2}? U.

Hello! On Pauls notes webpage, there is the following problem to be solved by variation of parameters: ty''-(t+1)y'+y=t^2 (1) On the page, the fundamental set of solutions if formed on the basis of the complementary solution. The set is: y_{1}(t)=e^t and y_{2}(t)=t+1 Now, I must be...

Hello! I have some examples of non-homogeneous ODEs to be solved by the undetermined coefficients method. Two from "Pauls math notes" page: y''+8y'+16y=e^{-4t}+(t^2+5)e^{-4t} The compsol. for this is: Y_{c}=C_{1}e^{-4t}+C_{2}te^{-4t} The first guess for a particular solution would be...

I need to fade the grid since I have to make a grayscale plot, the grid is very intrusive. Will layering achieve this effect?

Hello! Is there a way to regulate grid transparency in matlab? Thanks, Uku

I think I mixed up, the potentials subtract. Thanks!