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...

I am teaching an AP Physics class with Giancoli. In past years, I have not had problems with students over using the solutions manual that is easy to find online. However, this year these students seem to have no self control in order not to look at the sol. manual before they finish their...

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