Recent content by maCrobo

I think that is a doable problem for a kid of that age. I mean, the thinking is the following. How many sweets do I have? N. How many of them are orange? 6. On the total amount of sweets what portion is orange? 6/N. Then, what? I have 6/N orange sweets, (N-6)/N yellow sweets. mmh... How can I...

Hi, I would like to know how to treat a vector valued function when I want to know where are minima, maxima and saddle points. Thanks in advance!

I simply report what I read: "For an ideal gas, but for every kind of transformation ∆u=Cv ∆T, while for every kind of material in the thermodynamic system, but only for isochoric transformation ∆u=Cv ∆T." Where does this second statement come from? Everything is clear about ideal gases, but I...

Chrisbaird you are absolutely right, but in that "relaxation" state vectors that makes the field are kind of disordered in the space so not to have any sort of behavior like curling or diverging, then we can say the overall result is approximately zero in our set (portion of space). Practically...

Hi! Think about it mathematically to be sure of your result, so rewrite curl and div as \nabla. Then \nabla \times B=0 and \nabla \cdot B=0. This means that B must be parallel and perpendicular to the same vector, then the unique solution is B=0. In terms of Physics you that divB=0 by...

Thank you, guys for the answer, but I have already figured it out. Bye.

The problem ask me to find the tension on a capacitor after a switch has been opened. I have everything in terms of equations in s-domain and I'm sure they aren't wrong because I checked on the book. My unique problem is to understand a certain passage necessary to find the voltage knowing...

First: on the airplane there's no external E applied so F reduces to F= qvB. That's to say if you have a certain charge that moves in a magnetic field there will be a force applied on it due to its motion in the magnetic field. Second: Fx=W=- delta U; U=Vq. So (focusing just on magnitudes)...

Well I wrote down how to solve it, because I understand it may be difficult to see how the picture should be done if you have never thought about it before, but I haven't posted it because I want to focus on lorentz' law as I found it easier to explain what physically happen. Then you should...

Hi! You can deal with this kind of problems in two ways: using lorentz' Law or Faraday's Law. For Faraday's Law you should keep in mind that you need a closed circuit, so even if you don't practically have one you can imagine a closed path that suit your calculations. Just to follow you...

Yes it always true, either if f(x) is continuos on [a,b] or on (a,b). In the first case you have a proper integral, in fact the primitive F(x) is also continuos and the limit is the value of F at a (or b). In the second case you have an improper integral and in that case is necessary to use the...

Yes. You may imagine it by thinking it is 2 independently by x.

I'm not sure it may help, but I would deal with it by simply applying the definition of distance, that should be the norm of those vectors. So I would define X and Y as vectors of n components and show clearly, maybe with a few passages how they go to a and b.

Ok :P Last question: in the time domain I have a certain function for the power p\left( t \right)=\frac{1}{2}VI\cos \left( 2wt+ϕ_{v}+ϕ_{I} \right)+\frac{1}{2}VI\cos \left( ϕ_{v}-ϕ_{I} \right) from where we define the active power Pa to be P_{a}=\mbox{Re}\left[ \frac{1}{2}V\...

Did you mean power instead of current? If not: I don't get this point, if I follow Kirchoff's Law the current that goes out from a source can only be divided among the components of a circuit in case they are in parallel. I mean it can't be that the current that get to an inductor is greater...