Recent content by myself

We only need to see how much the volume of water increases. If the lead is in the boat, it displaces water equal to its weight (so it floats). If the lead is in the water, it displaces water equal to its volume (so it sinks). Since lead is denser than water, it displaces more water in the boat...

ah, but the resistance is always constant, whether there is voltage passing through it or not. If you have the resistor hooked up to a 6 volt battery, the resistance is still 220 ohms. True, there is a 6 volt voltage drop across the resistor, but the resistance is constant. It's harder to...

Perfect elastic collision is a collision where no kinetic energy is lost during the collision (so there is no sound and no friction during the collision). This occurs on the atomic level (for example gas particles collide basically elastically)

Generators in general make alternating current through the method of electromagnetic induction. In most power plants they rotate a coil of wire through a static magnetic field. Through half the rotation of the coil of wire, the electricity flows one way, and through the other half of the...

How exactly is energy stored inside an electric or magnetic field? I read some formulas in a book, and I get the derivations, but I do not see how there is energy in the electric field, of say, an electron. Does anyone know how conceptually, energy is stored in a field?

I guess I wasn't very clear at first. First of all, this isn't really a homework problem, but I found a section about transformers in the textbook, and I didn't find the explanation comopletely helpful. I couldn't figure out how side A knew how much current to "send" to side B. I know how...

Draw a free body diagram for the first case. Notice that the sled is in equilibrim because it is moving at a constant velocity. Therefore, all forces sum up to zero. Then, it is possible to figure out the coefficient of friction, which is used to solve the problem.

Let's say that there is a transformer with 10 loops on one side (side A) and 100 loops on the other (side B). If ther is a rms 10V potential difference produce by a generator on side A, then there would be a rms 100V potential difference on side B. It would seem like the resistance through the...