Recent content by mtr

Well, I won't argue with that ;) There were no additional information. They also do not say anything about the bottle's shape, so I suppose it can be any.

That's right, but considering the wavelength, we know, that \lambda = 2L so when L decreases, lambda decreases proportionally to the 1st power of L and inversely proportionally to the 1st power of V. I can see my mistake. In fact it is lambda inversly proportional to V so f is directly...

It depends on friction. Is there any friction in this task? If yes, tensions are not equal. What about masses? Are they among the data? Considering acceleration, it seems it will be a-g. In your equations you just have to change g for g-a and a for b-a, where b is acceleration of each mass if...

Homework Statement There is a plastic bottle into which we blow in such a way, that we receive a sound of freguency f. The bottle is filled with water that has volume V. Prove, that f=f_{0}(\frac{V}{V_{0}})^{\alpha}, where f_{0}, V_{0}, \alpha are constants. Homework Equations The Attempt...

That's true, but still there is the capacity which wasn't used. I think that there might be something about impedance, as Irid suggested.

That's right, the capacitor and the diode are connected in series. I suppose they are considering here and ideal diode, otherwise there should be something about its properties.

I don't exactly understand what you mean. How can we obtain a voltage using C? And is E the EMF or the stored energy in the capacitor?

What about C?

So it seems, that I have to find the maximum value of the EMF and it will be the voltage on the capacitor. Am I right? On the other hand what is the capacity C for? It is among task's data, but it hasn't been used yet.

Actually, the EMF is produced by a pendulum in a magnetic field, with period 2T. Isn't there any drop of voltage that is connected with the diode?

So after a long time the capacitor is charged completely, but still how can I find the voltage? Does it equal EMF? Or maybe I should find Q somehow and use C=\frac{Q}{U}?

I am looking for B at the point in the centre of the hole of the ring. So actually in this case I should use B=\frac{\mu _{0} N I}{l} ?

Homework Statement There is a circuit which consists of a capacitor with capacity C, a diode and a source of changing EMF such that during time \frac{1}{2}T EMF equals E and during another half of T it is -E (current flows in the opposite direction). What will be the voltage on the capacitor...

So why do I need N - number of waps? Usually known data should be somehow used in such problems. R_{1} is the radius of a hole inside a ring and R_{2} is the radius of the loop of current.

OK, it forms a torus. For sure.