Recent content by Jim L

I was assuming that the length of the solenoid is not the length of wire needed to construct the solenoid. It is the length of the "form" the wire would be wound on to construct the solenoid.

I'm wondering why pi is in your formula for calculating the number of turns?

For what it is worth, with spur gears the teeth roll over one another; with worm and worm wheels the surfaces slide against one another. This should give some idea of the friction losses involved. That is the way I see it.

If V= I/R you have discovered some new relationship.

Greetings- Please give me the title of a book on QM that is often suggested for a beginner.To aid in the selection, I have a MSEE degree. Thanks.

I am no expert, but I get the books answer, based on y=- ln (cos x)+C, and C =3 - ln[(sqrt2) /2)] , which = 3+ ln (sqrt 2). Or y=-ln (cos x) -ln ( sqrt 2 ) +3 y= - ln [ (cos x) sqrt 2] +3 Dont bet your life on it. Jim

I've got it. I was equating the authors F sub x, which can contain x,y,z and is the multiplier of the unit vector i, with f of x. Still cannot see how the partial der. of -2Z wrt z can be anything but -2. How the chain rule applies and generates a multiplier of 2evades me. But it has been a...

Sorry, the value IS -c/2. The way I see it: f of x can be anything, such as x^2 +3y. f of y can be anything , such as 4y-2x f of(-2z) can be anything , such as 4z+2y Also, cannot see how df(-2z)dz= -2 f'(-2z), assuming f' is the partial of -2z wrt z. Or is df mean partial der? Either...

Been working my way thru H.M. Schey-been out of college for 50 yrs. This problem has me stumped. F (of x,y,z)= i (f of x) + j (f of y)+k f (-2z). F is a vector function, and i,j,k are unit vectors for x,y,z axis. The problem is to find Div F., and then show it is 0 for the point c,c...

Thanks,now if you can help me figure out how to convert Cartesian unit vectors to Cyl. Coordinate unit vectors, I will be even more gratefull. Jim

Thanks, but I still do not understand how to take the limit as delta r and delta theta approach zero. Jim

Greetings- out of college for 50 yrs and studying H.M. Schey's book. Cannot understand his derivation of the z component of the curl of a vector function F for a part of a sector of a circle in a plane parallel to xy axis. Cylindrical components. Let me describe equation as three parts for ease...