Recent content by bodensee9

Homework Statement Hi, Let's say that I measure the position of a system and I get that it is at X. So then if immediately after I measure the momentum, will I get: 1/sqrt(2*pi)* integral (exp(ikX))*(exp(-ikx))dx? But this integral is undefined? Then how do I find the momentum wave...

Homework Statement Hello: I have a say N = 7 vector. Say I know that it's DFT is X = [X[0] X[1] ... X[6]] I am wondering if there is any way that I can find the sum of: x[1] - x[2] + x[3] - x[4] + x[5] - x[6]? Since N = odd, I can't use the trick with N/2 = pi as a frequency. Thanks so...

Hello: I have the following: Homework Statement A wire of unstretched length l is extended by a distance (1/1000)l when a mass M is hung from its bottom end. If this same wire is connected between points A and B that are at a distance l from each other on the same horizontal level, and...

they would be, but I thought then you must have that F is the curl of some other function. So if div F = 0 then it would be true. But would it be true if div F is not zero? Thanks.

Hello: I usually think of Stoke's Theorem as: \oint F\bullet dr = \int \int curl F \bullet dS where dr is over a curve C and dS is over a surface sigma. But today in class the instructor said that Stoke's Theorem can also be used to change the surface over which one is intergrating, so...

Hello: Thanks, so would the equation for a sphere be: x^{2} + y^{2} + z^{2} = R^{2} So then my constraint is z^{2} = R^{2}-x^{2}-y^{2}? And then my function would be to maximize: x^{2}y^{2}(R^{2}-x^{2}-y^{2})? Thanks.

it's a hemisphere, I would think that z would be all positive because I am assuming that it's the upper hemisphere. I am going to use either Lagrange multiplier's method or the usual gradient = 0 method. I am sure the answer will be some multiple of R.

Homework Statement Hello: This is a max/min problem. I am asked to find the rectangular box of maximum volume inscribed in a hemisphere of radius R. Homework Equations So I am wondering if I have set up this correctly. If say my length is x, width is y, and height is z. So, I would...

Hello: Yes, but for some reason, I'm supposed to find the rate of approach (the tower). And the answer is 266 mph. But I'm not sure how I'm supposed to get that answer from what I have? Thanks.

Homework Statement Hello: An airplane is flying near a radar tower. At the instant it is exactly 3 miles due west of the tower. It is 4 miles high and flying with a ground speed of 450 mph and climbing at rate of 5 mph. If at the instant it is flying east, what is the rate of approach to...

Thanks!

Hi I have a general question about the definition. I know that a curve parametrized by t is smooth if the derivative r'(t) is not 0. I assume this is the 0 vector? So then does that mean that if we have r(t) = f(t)i + g(t)j + r(t)k then any of the two can be 0 simultaneously while the...

Oh sorry, but never mind. I will just use old Kirchoff's Laws and write down the expression fot voltage across the 2 loops, and then derive the answer that way. Thanks anyway.

Homework Statement Hello: I've this circuit: -----Resistor (100000 ohms)---/ (switch) ------- | | |A Battery Capacitor Inductor | |...

if the sheet were the computer screen, then z would be into the page if the current were flowing to the left. I was thinking if the sheet were along the y-z plane, and the current were flowing along the y direction, then z would be pointing upwards. Does this mean that we have another field...