Recent content by al33

In the nuclear physics, why do we say that the total angular momentum J is zero when the proton number Z and the neutron number N are both even?

Wow, thanks for the link and the editing part. I should and sould not have posted this thread. I posted so that I could see all of these great derivations. I should not because I am afraid that I have wasted some of your time. I made a mistake interpreting the result for the N loops. That’s for...

If we place many rings side by side, it looks just like a solenoid, right? And if we apply Ampere’s law on both cases, aren’t we supposed to get the same result? If not, how come? There must be some point that I haven’t figured out.

I don't understand something. At the center of N circular loops, the magnetic field is μ_0NI/2a. And that for a solenoid is μ_0nI. Why are they not the same when the number of loops is large and the length for the solenoid is long?

Why aurora happen near north or south pole more easily? I mean why charged particles can escape the Van Allen belts more easily to have collisions with particles in the atmosphere? Why are they harder to escape near equator? Isn't it supposed to have weaker magnetic field near the equator?

I think so, before challenged. It is the position when kx equals mg. And the kinetic energy gained then can be thought of just as the potential energy lost with respect to the new equilibrium position only. For the spring stretched down from that equilibrium position and let go, we don't need to...

Right! I was confused by taking the compression case into the consideration.

Soon after I posted that question, I figured it out. For small oscillation, the spring with mass is always moving with a total length longer than its natural length, which means no matter what position it is at now, its potential energy is never zero. And this reaches its maximum at the bottom...

Yes. So, (1) moving up from the equilibrium, potential energy of spring increases, gravitational potential energy increases (less negative) (2) moving down from the equilibrium, potential energy of spring increases, gravitational potential energy decrease (more negative) Is that correct?

I'm stuck with a solution to the vertical spring with a body suspended. The solution says that when the body's gravitational potential energy is decreasing, the spring's potential energy must be increasing. How is this correct? I understand the analysis leading to the result that the vertical...

This is a fundamental physics lover who is dedicated to physics education.