Recent content by Planck const

I know that the physical meaning of SU3 and SU2 - you can change the places of the quarks or/and leptons and you will get the same results. What is the physical meaning of U1, and O3,1 (Lorentz group if I am not wrong)? I know U1 is connect with the Polarization of the light. Thanks...

The answer is simple. (I will call sigma -> rho) if dE/dt (partial derivative) = 0 ==> (Gauss law) d\rho/dt = 0 ==> (math) \rho is constant in time. (stationary current) And you can see in the problem data, that they didn't say anything about the function \rho .

Homework Statement Stamp of iron the his mass - M and temp' - T0 (T0>100 C deg') has been placed on cube of ice. The mass of the ice - m, the temp' - t0 = 0 C deg' How many present of the ice get melt? Homework Equations Q = mc\Deltat The Attempt at a Solution If I let...

What is I? its the relation betwwen the charge (you know it from sigma) and the period (you know it from w) The charge inside the cylinder its Sigma*A(r) (and not all A!) What is the integral of B*ds ? its the product of B and the scale circuits that thir radius its r (r<R) You need to...

Ok Need erg and not Jaul ... 1 cal = 4.2 J = 4.2*10^7 erg K*L / g = 5*10^-3 * 79.7 * 4.2*10^7 / 980 = 17,025 cm = 170.25 m Thank you very much!

Let's see... cal = 4.2 J so I need to multiply L in 4.2 and I get: h (cm) = K*L*4.2 / g = 4.2 * 5 * 10^-3 * 79.7 / 980 Using pocket calculator, h = 1.83 * 10^-3 (cm) ! In the book - 1.7 * 10^+3 About the math singles in this forum... I am used to the way that I write. Thanks anyway :)

Thanks for the reply! The initial temperature of the lake water = 0 C deg' L of water = 79.7 cal/gr K in the book = 5*10^-3 (no units) g = 980 cm/sec^2 The answer in the book is the the height, h = 171 m = 17,100 cm (!) Now all the potential energy become kinetic and its become...

Hi.. looks like simple problem but the result i got is unreasonable. Homework Statement There is lump of ice, that falling down into a lake that his temperature is 0 celsius degrees. K of the lump getting melt ( = M that melt/M ) What is the height that from him, the lump fell ...

You are not answering me. If someone ask A or B, you need to say - A or B I didn't understand - with cos or withnt?

OK... My question is, if I have so system like square loop... and all the donations be summed up by Bcos(Tetha) or sin(Tetha), am I need to multiply the cos/sin in Biot -Savart rule? So I will get dB=const*dx * sinTetha*cosTetha / r^2 or I just need to exchange cos with sin? (if all...

Homework Statement What is the field? I just want you to chek my solution (just the begining) (math) You can see the paint. Homework Equations Coulomb rule The Attempt at a Solution 1. tan(Tetha) = r/a => r = a*tan(Tetha) => dr = a/cos^2(Tetha)d(Tetha) 2. dq = Sigma * da =...

Thank you very much!

Reply Zeal - Thanks:) Im not sure about the area.. Is it 2Pi*b*L...or 2Pib^2. I chose the secen - 2Pib^2 becuse I tought L (lenght) won't be reduced. c = velocity of light Troglio - So which law will worked?! about your idea... I will get +B and -B ? because its one dimension (the...

Look here: http://imageshack.us/photo/my-images/545/thep2.jpg/ I didn't learn about solid angle :shy: So.. I geuss sintheta Is h/r ? or sqrt(h^2-b^2/16)/r ? Am I right? Thanks in advanced

Homework Statement First I have to say that my English isn't good:) Ok.. There is a cylinder that at him, there is hole. Cylinder radius is "a" and the hole radius is "b" The distance from the cylinder center to the hole center is "d". The current density is "J", in the hole there is...