Recent content by nietzsche

Homework Statement If we have two vibrations with angular frequencies ω1 and ω2 with ω1≈ω2. Then we will have beats with beat frequency ω1-ω2. But suppose we have two different phase constants, for example x1 = Acos(ω1t + ϕ1) and x2 = Acos(ω2t + ϕ2). What happens to the beat frequency...

You can't sub in 0. You're looking for numbers c such that f(c) = 0, not what the values of f(0) are.

Thanks, I'll have a look!

Homework Statement Find the surface area of the ellipsoid (x/a)^2 + (y/a)^2 + (z/b)^2 = 1. Homework Equations If G(u,v) is a map from R2 to R3 that parametrizes the surface, then the area of the surface is equal to the double integral over the domain of G of the norm of the cross...

Homework Statement \text{Show that the series }f(x) = \sum_{n=0}^\infty{\frac{nx}{1+n^4 x^2}}\text{ converges uniformly on }[1,\infty]. Homework Equations The Attempt at a Solution I think we should use the Weierstrass M-test, but I'm not sure if I'm applying it correctly: For...

Homework Statement \text{Show that }\sum_{n=1}^{\infty} \left( \frac{e}{n} \right) ^n \text{converges.} The Attempt at a Solution I think we should use the root test. \lim_{n \to \infty} \sqrt[n]{\left( \frac{e}{n} \right) ^n} = \lim_{n \to \infty} \frac{e}{n} = 0 < 1 So the...

thank you so much willem. i don't think my prof worded the question properly, so I'm going to ask him tomorrow. thanks again!

Homework Statement Two strings with otherwise identical properties differ in tension by 0.25 N. If both strings are struck at the same time, what is the resulting beat frequency? Homework Equations frequency is proportional to the root of tension? The Attempt at a Solution I...

Homework Statement Two radio frequency sources broadcast waves of the same frequency. They are placed 1.0 m apart. Let the x-axis be the line from one source to the other, and let x = 0 be at one of the sources. Nodes are observed at x = 0.24 m, x = 0.49 m, x = 0.74 m. 1) What is the...

Thank you, but I still don't understand. I'm really trying to get some intuition behind why we are able to do this. I can see that vt is equal to the distance that one crest will move in time t if it is moving at wave speed v. I can also see that if we put t = 0 in the new equation, we get the...

Hi everyone, I'm trying to understand the derivation of D(x,t) = A \sin{(kx - \omega t + \phi_o)} which is the displacement equation for a sinusoidal wave. The way my textbook (Physics for scientists and engineers by Knight) does it: Look at the graph of displacement versus position at time...

Hi PF. This is a homework question, but it's for symbolic logic. Figured that it didn't really make sense to post it with the math and science questions, although I'm sure people on there would know how to solve it. I'm having trouble constructing a derivation for the following: For all x...

Thanks Redbelly. I suspected it had to do with some antenna affect. It's still confusing though... it's so hard for me to understand things when they're invisible.

Hi PF, it's been a long time since I've posted on here. I have a lab due soon and it was regarding oscilloscopes. This isn't really a homework problem so I'm not using the template... Anyways, when I held the input lead in my hand, the amplitude of the wave displayed on the screen got much...

thanks man! i always forget about that crazy wolframalpha thing.