Recent content by pious&peevish

Ah, now it makes perfect sense! Thanks!

Yes, sorry - I meant ∫∫ √((fx)^2 + (fy)^2 + 1) dA . I had √(x) for ∂f/∂x and √(y) for ∂f/∂y.

Homework Statement Find the surface area of the surface defined by: z = (2/3)(x^(3/2) + y^(3/2)), 0 ≤ x ≤ 1, 0 ≤ y ≤ 1 Homework Equations SA = ∫∫ √(fx)^2 + (fy)^2 + 1 dA The Attempt at a Solution Solved for the partial derivatives and plugged them into the formula, but got a...

Thanks a ton - that was right!

Hmm... I tried that and it didn't work either. Is there something fundamental I'm not grasping? That's what I'm most worried about now.

OK. So just to confirm, if I wrote that 2*(thickness) = [(number of minima) * (wavelength)] + [(1/2)*(wavelength)], would that be right?

Thanks! But when I plugged in the values into the equation 2*(thickness) = (number of minima) * (wavelength), I didn't get the right answer... there must be something I'm still missing, but I don't know what it is.

Homework Statement Two flat slides of glass are separated at one edge by a thin wire, as shown below. The top surface of the upper slide and the bottom surface of the lower slide have special coatings on them so that they reflect no light. The system is illuminated with light of wavelength...

Thanks! I got the right answer.

Oh, wait - should I multiply that by sin(187 rad) instead?

So... would V (rms) be 110 V * (sqrt(2))?

Thanks! It doesn't say whether or not the secondary voltage (13.9 kV) is an rms voltage... should I assume that it is?

My textbook doesn't cover transformers in very much detail at all, so I only have a very vague idea as to how they work... Homework Statement The secondary voltage of an ignition transformer in a furnace is 13.9 kV. When the primary operates at an rms voltage of 120 V, the primary...

OK... something odd happened. I got the correct answer for 9c, but for some strange reason the corresponding answer to 9b was marked wrong. I already found from 9a that w (omega) = 187 rad/s. I did Z = sqrt[(11^2)+((187*2.07)-(1/(187*(13.8*10^-6)))^2)], and this simplified to Z = 11.007...

This one is quite comprehensive and gives a very general overview: http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods It can also be downloaded as a PDF.