Recent content by dgreenheck

I am doing an analysis concerning the torque-free motion of an axisymmetric body (J1 = J2 != J3). The angular velocity is given \omega(t) = [\omega_t\ sin(\Omega t), \omega_t\ cos(\Omega t), \omega_{z0}] where \omega_t, \Omega and \omega_{z0} are constants. I would like to determine the...

I realize this is 2 years late... but better late than never right? Your math is wrong. You should have ended up with \omega^{6} - 231\omega^{4}+19600\omega^{2} = 400 There is only one real, positive solution to that equation, which is the gain crossover frequency.

My question can be simplified so that both solenoids are a thin shell instead of having a finite thickness. I'm just wondering how one solenoid within another reacts.

Imagine a finite length solenoid with outer radius R1 and inner radius R2. This solenoid has a time-varying current going though it. This solenoid is also fixed so that it cannot move. Now imagine another solenoid, coaxial with the first, with its outer radius equal to R2 such that it can slide...

I meant to say for the same current. All that is happening is the core is being inserted or removed. But I understand now, thank you.

Okay, both of your responses make sense. Is there ever a time where you would have the same B, though? If the B field is always dependent on the permeability of the material it's flowing through, the squared factor of mu on top will cancel out the factor of mu in the denominator and the energy...

I have a question about solenoids. The formula for the magnetic field energy density is: \frac{1}{2}\frac{B^{2}}{μ} If I have an air-filled core, then μ=μ0. If I have a steel core, then μ will be ~ 100μ0. This implies that an air-filled core solenoid stores more energy than a steel core...

The charges are of opposite sign and of equal magnitude.

Homework Statement There are two point charges aligned on the X-axis. Charge A is a distance -d/2 from the origin and Charge B is a distance d/2 from the origin. What is the potential at a distance z above the center of the charge distribution? To further clarify Charge A location at...

Homework Statement Suppose that u(x,y) is a solution of Laplace's equation. If \theta is a fixed real number, define the function v(x,y) = u(xcos\theta - ysin\theta, xsin\theta + ycos\theta). Show that v(x,y) is a solution of Laplace's equation. Homework Equations Laplace's equation...

Remember R and T are the reflection and transmission "coefficients" which are between 0 and 1 while r and t are the reflection and transmission "amplitudes" which are (k1-k2)/(k1+k2) and (2k1)/(k1+k2), respectively.

When calculating the kinetic energy of a rotating water molecule (translational and vibrational motion not important here), am I correct in assuming that you do all the calculations from the center of mass and analyze each axis of rotation (x,y,z)? The bent geometry is throwing me off! Any...

When calculating the kinetic energy of a rotating water molecule (translational and vibrational motion not important here), am I correct in assuming that you do all the calculations from the center of mass and analyze each axis of rotation (x,y,z)? The bent geometry is throwing me off! Any...

For anyone referencing this thread (like I am), the force on the block is just Mg-T2.

Ah, perfect examples. I think the problem was I never really relayed what my misunderstanding was. You can consider this case solved :) Thanks very much guys I really appreciate it.