Recent content by chrisk

This is a Symon problem. I found the given expression for the torque is incorrect. Attached is the solution and an explanation of why the solution does not agree with textbook. I know the policy is not to provide solutions but in this case it's necessary to show the error in the stated problem.

Hi Greg, I composed and sent an email via Physics Forums Comments to admin on July 3, 2021 asking about posting a few of my web pages containing solutions to undergraduate physics textbooks no longer used for associated courses. Please reply if you received the email. Thanks, chrisk

Try writing the Lagrange equation with the friction term included then transform to the Hamiltonian expression. Then ponder, "is this a conservative force and how does this effect Louisville's Theorem?"

Review this website for an explanation of the Minkowski Force components and the dot product of u with E...

Phase shifts of pi and 0 occur at normal incidence for s or p polarized light. Ellipsometry uses oblique angles of reflections and compares the phase shifts after reflection of the two states of polarized light. See the below link for a brief tutorial of ellipsometry...

Given that this is a past exam, answering your questions should be within the guidelines of Physics Forums. So, i) What are the two postulates of the theory? ii) Use these postulates to derive the desired expression. Hint: Pythagorean Theorem. iii) The result from ii) can be used.

Go to the below website for a good set of notes on plasmas. This should help clear up your questions. As for the dark space, the acceleration of the electrons, due to the applied electric potential, within this region does not produce the necessary velocity to create excited gas molecules...

The darkness of a sheath is a result of insufficient electron energy to create excitation of gas molecules hence no spontaneous emission of photons. What do you know about electron and ion plasma frequencies so as to provide a starting point?

Please show relevant equations and an attempt at the solution.

Begin by plotting the effective potential with respect to r and look for turning points.

Your statement about friction opposing the direction of velocity is correct. Since Ff = wv the minus sign for Ff provides the correct direction of the frictional force. Regarding the volume, it's part of the bouyant force expression. You can state that V(z) = V(-z) in the ODE and leave Fb as...

Consider an electron beam directed at a screen with a vertical slit of width delta y and a photographic plate a particular distance behind the screen. As the width of the slit narrows the accuracy of determining the vertical position of the electron increases. But, electrons behave like waves...

This can be viewed as a one dimensional collision problem because the horizontal velocities are equal. View it as two molecules traveling in a car at a constant speed in the x direction. An observer in the car only sees the molecules moving in the y direction with opposite velocities. The...

With a force pointing up as positive the net force, F, acting on the object is F = -Ff + Fb - Fg So, is your sign convention correct?