I like the candy/kid analogy, but is there a way to show mathematically how E/B = c even when E and B are zero? Or at that point, do we have to do the ratio of the amplitudes?
My textbook (Serway and Jewett, Physics for Scientists and Engineers) says that Emax/Bmax = E/B = c. And that E and B are in phase. My question is, if they are in phase, they both reach zero at the same time. At that point, E/B = 0/0 and not c. I know I am missing something, but not sure what...
In using the Biot-Savart Law for an finite wire, I am having trouble understanding the angles. I have sintheta1-sintheta2, where theta1 is measured from point P to the horizontal wire and from the vertical axis, to the left of point P. Theta 2 is measured to the right of point P.
I am ok until...
there was no external resistor. The voltmeter itself (the multimeter) has a resistance of 10Mohms. But, what do you mean disconnect the output? Do you mean remove one of the wires leading into/out of the power supply?
No, the battery has an on/off switch. It was not just my group where this was happening. It happened to all the groups. We tried first with a 2.2 micro-F capacitor, and since it discharged too fast, we switched to a 4.7 micro-F capacitor. I don't know if that affects anything.
The voltmeter was a digital multimeter. The initial fall in the voltage was very quick. No matter what voltage we started at, either 1V or 20V, it seemed to drop down to close to zero almost immediately, then climb back up to about 1V in about 10seconds, then begin it's steady decline back down.
In lab, we built a circuit with a 4.7 micro-F capacitor hooked up to a DC source. In parallel to the capacitor was a 10megaOhm resistance voltmeter. We used the voltmeter to find the voltage drop across the resistor and find the RC constant (supposing unknown C). We would turn on the battery...
OK, so the force between me and Earth is G*m1*m2/r^2, and I have the same pull on Earth as Earth has on me. I see it in the math, BUT, it doesn't make sense to me outside of the math. Earth's gravity pulls me down to the surface...certainly I don't pull up on Earth with the same force? Why is...
the observable universe is finite in extent, but we can see out to the cmb. Isn't that the very first few minutes after the big bang. Outward from the cmb (back in time) there was coupled light/matter so we wouldn't be able to see it anyway. But if we see the cmb, and the cmb defines the...
Ok, but if there are stars who are younger than the cmb, which I'm assuming all stars are, then shouldn't we be able to see all of them? Saying that there are objects whose light hasn't reached us means they are older than the cmb? Or, stated another way, can we see everything withing the...