Recent content by kq6up

Thanks Bill. I do remember going through this treatment in grad school. And I was impressed as it showed how the E and the B fields are equivalent, and that they only thing that affects whether it is an E or a B field was if you were translating with respect to a rest frame. I will take a...

I gave a short Maxwell's equation history lesson and included a quick explanation of the connection to Maxwell's predecessors. Just wanted to see if I hit those points right. I don't think I made any physics mistakes, but this was a little more conceptual with some calculus flavor as the student...

Wow, I did not know that all of these conundrums existed. I think I heard the statement I posted above from Leonard Suskind's lectures. I said it during a lecture yesterday, and realized that this is not true as I would not be able to know the kinetic energy of the system without knowing the...

I have heard it said that in classical physics that if one knows all the particles of a systems momentums and positions, that the evolution of the system can be completely known. I would imagine this also would have to include the nature of all the forces acting on the particle. Also, for...

Ah, I see that it would be ##\frac{T}{4}##, and that would be ##\sqrt{\frac{m}{k}}\frac{\pi}{2}## I see my error. I confused ##\sin^{-1}1## with ##\tan^{-1}1## which was an earlier result. Thank you, kQ6Up

Homework Statement [/B] A block of mass m slides down an incline with a height h. Later, it collides with a spring and compresses the spring to some maximum displacement. How long does it take to reach maximal compression.Homework Equations [/B] 1) ##mgh=\frac{1}{2}mv^2+\frac{1}{2}kx^2## 2)...

Here it is fixed for the record.

Yes, that is a typo. Thanks, KQ6UP

Ok, I used .43kg, and I get: ##v=\sqrt{2gh}## implies that ##v=4.43m/s##. I used ##I=\Delta \boldsymbol{P}=\boldsymbol{P}-\boldsymbol{P}_o## Then componentized: ##\boldsymbol{P}_o=-1.90kg\cdot m/s \cdot \hat{y}## ##\boldsymbol{P}=18 m/s \cdot .43 kg \cdot (\cos 55^o \hat{y}+\sin 55^o...

Homework Statement A punter drops a ball from rest vertically 1 meter down onto his foot. The ball leaves the foot with a speed of 18m/s at an angle of 55##^{\circ}## above the horizontal. What is the impulse delivered by the foot (magnitude and direction)?[/B]Homework Equations...

Not sure why you are using virtual work either. I would attack this problem with mechanical advantage of a system of pulleys. Regards, KQ6UP

The Schrödinger's cat thought experiment was conceived by Erwin Schrödinger to explain the awkwardness of the Copenhagen interpretation of QM. If a QM system is in a superposition of states, what actually causes the collapse? There is obviously a collapse according to the Copenhagen...

I got hired on the spot :D Thanks guys/gals, KQ6UP

You know what I just noticed. The vectors are darker or lighter (not longer or shorter) depending on the strength of the ##\mathbf{B}## field. So that is a hint, and from that info -- you should be able to figure it out. Regards, KQ6UP

What bearing on how close together the turns are should effect the magnetic field. I do not see this happening in this Java model. This is the "turn density" or "winding density" and it is equal to ##\frac{N}{L}##. The magnetic field is proportional to the turn density and/or the current, not...