Recent content by anizet

OK, so my result was correct. But could somebody explain to me the physical meaning of it? It is not intuitive...

Homework Statement The expression for electric charge on the capacitor in the series RLC circuit is as follows: q(t)=A*exp(-Rt/2L)*cos(omega*t+phi) where omega=square_root(1/LC-R^2/4L^2) What is the phase phi, if the initial conditions are: q(t=0)=Q I(t=0)=0 Homework Equations The damped...

Well. I'm not sure yet. Thank You any way.

yes, that's what I mean.

I mean that after 20 hours N=N0/e.

Homework Statement A nucleus decays into two channels with probabilities 0.62 and 0.38, respectively. Its lifeime is 20 hours. What are the decay rates into each of these channels? Homework Equations If there is only one channel of decay, the decay can be described by the formula...

I know the formulas for efficiencies e of heat pump (it is e<=Tmax/(Tmax-Tmin)) and refrigerator (e<=Tmin/(Tmax-Tmin)), where Tmax and Tmin are temperatures of warmer and colder (respectively) involved containers. These formulas make me puzzled, as efficiencies seem to be possibly bigger than 1...

Homework Statement A convex lens (f1=300mm) is placed 200 mm from a concave lens (f2=-50mm). An object is placed 6m away form the convex lens. (the order is as follows: object - 6m - convex lens - 200mm - concave lens). Determine the position, magnification and nature of a final image...

One more correction: Why should I integrate from infinity to r not from zero to r? I hope, now it's ok...

Sorry again: from inf to r not from r to inf, I meant.

Thank you very much for the reply! I have just one more question: why should I integrate from infinity to zero, not from zero to infinity?

I made a small mistake in typing the formula on V that I obtained. It should be: V(r)=-q*r^2/(8*PI*e0*R^3)

Homework Statement A charge is distributed uniformly throughout a non-conducting spherical volume of radius R. Show, that the potential at distance r from center (r<R) is given by: V=q(3*R^2-r^2)/(8*PI*e0*R^3) Homework Equations From Gauss low: E(r)=q*r/(4*PI*e0*R^3) E(r)=-grad(V(r))...