Search results

Tell him to take physics again because he clearly missed the point. Yes, 1000 watts is 1000 watts, but a heater turns (most) of that energy to thermal energy whereas any other device converts some of that energy to some meaningful work. But you want an example. So let's say we have a (massless)...

This is more of a math question I suppose, but its in the context of calculating the second order energy shift in the ground state energy for a non relativistic collection of electrons. We end up showing that the energy shift has a finite and divergent piece. The divergent bit is proportional...

Homework Statement Obtain the analytic expression for the N-channel T-matrix assuming a separable potential. Hint: assume that T is proportional to V. Specialise your answer to N=1 and perform the required integral to get an explicit form for T, assume the given form for g(k)...

Ok, solved the problem. It was really stupid too. I was throwing "0" into the subroutine but i had to define variables that are zero to put into the code. Rookie mistake.

Hey folks, I'm having an issue using a routine from the netlib that is supposed to calculate eigenvalues and eigenvectors. The canned routine can be found here: http://www.netlib.org/seispack/rgg.f I want to find the eigenvalues of a matrix (a more complex hamiltonian), so for my simple...

Thanks for all the tips folks.

Ok, I'll add that one to the list. I'll also peruse my copy of Fowles and Cassiday to see if there's anything helpful in there.

Unfortunately my undergrad mechanics completely omitted Lagrangian mechanics and everything thereafter, so this is the first time, heh.

Thanks Fred, I'll hit the library up tomorrow and look for those :)

Sounds about right then. If I get 6 hours of sleep I consider myself lucky.

The book we're using for mechanics is "Theoretical Mechanics of Particles and Continua" by Fetter and Walecka. I've never had as much trouble understanding physics as I am now. I am absolutely confounded when it comes to Lagrange multipliers, Euler angles (and other rigid body stuff) and...

Well f^{-1} : B \rightarrow Y So let x be in B as you said. Now f^{-1}(x) is an element of Y provided that there is some y in Y such that f^{-1}(x) = y . This is where you need to use surjectivity. Hope this helps.

Just an fyi, in high school I absolutely hated math. Nothing really "clicked" until I hit calculus. At that point, the reasons for all previous work became obvious. Maybe check out some lectures on youtube before deciding you can't put up with the math.

So in part a, you seem to have a "g" floating around. It looks like you assumed the final potential energy is gravitational. The final potential energy should be for electric charges, neglect gravity.

Any time you prove subset relations, you have to show that any element of the subset is an element of the parent set. Let x be an element of the subset, show it is in the parent set.

So a general way to go about kinematics problems: - Note that in all of the equations only 5 variables appear: t, \Delta x, v, v_o, a - These represent time, displacement, final velocity, initial velocity and acceleration. - Each individual equation only contains 4 variables. - Generally you...

Kinematic equations are listed here. http://www.physicsclassroom.com/class/1dkin/u1l6b.cfm Its like the 2nd hit on google when you search for it.

So the equation you listed, V^2 = V_o^2 +2a \Delta x Has 4 variables, none of which are time. I suggest you look at the kinematic equations and select the one with all of the variables you have and need to solve for. So the variables you already know (or can deduce) are what? (ie...

Yeah, that was the TeX problem. Thanks :) Also, it might be of interest to know that: \left| r_{i,j} \right| = min( \left| x_i - x_j \right|, L - \left| x_i - x_j \right| )

The problem is with calculating the force of a particle by another particle while both particles lie on a torus. By this I mean, if particle i and j are in a box (LxL) and particle i is on the left edge of the box and particle j is on the right edge of the box, the distance used in the force...

So I've convinced myself that my updating of positions is valid. However, I am still receiving final positions outside of the box. This is my entire code. Perhaps someone can find the error. Note, I intend to randomize the starting positions and velocities once I get this to actually work. ...

Final shameless bump before abandoning hope for a reply.

You should just have to move all the terms with I3 to one side of the equation and factor out the current. That should give you an answer for I3.

Looks good. Didn't check numbers. Glad I could help. Good luck on your future physics endeavors.

You could write 3^(x+1) = 3^x * 3^1

So the spring is hanging. Its not accelerating. Its just dangling there. So sum of forces is zero. Try that.

Shameless bump of thread.

I'm assuming its not something silly, like using grams instead of kilograms or having your calculator in radian mode as opposed to degree mode, correct?

Ah. The force of static friction varies. The coefficient of static friction is used when you want the MAXIMUM value of static friction, ie just before the object starts to move. As an example: If a block on an incline had a normal force of say 10N and the coefficient of static friction was...

Hint: If the coin is moving, should you be using the static coefficient or the kinetic coefficient.

So I'm working on a problem where you have 100 argon atoms in a box that obey the Lennard Jones potential. We're using the Verlet method to calculate the position of each particle at the next time step. The issue I'm having has to do with our boundary conditions. We assume that atoms are on a...