Recent content by bobaustin

Anyone ever heard of physics author named "Hilary. D. Brewster"? http://mlbd.com/AuthorDecription.aspx?id=10950 Hilary D. Brewster Hilary. D. Brewster is a well known author of some best selling books on topics that prominently includes Relativity, Digital Electronics, Fluid...

Are they Latin or Greek characters? Do I say "chi" and "zeta" or "eks" and "zee"? Thanks

Redbelly98: Thanks for a great explanation that makes perfect sense!

But if you can't ignore the pulley then the tension on one side is different than the other side, right? For example if you have a ("low friction") Atwood machine, the T is the same on both sides which is why you get a = (m2-m1)g/(m1+m2) etc, but in a problem where they talk about the pulley...

You have N perpendicular to the surface, mg straight down and friction acting along the surface. N sin theta - friction cos theta is the net force that gives you centripetal acceleration (along the horizontal) Friction is mu times N or mu times mg/cos theta. So everything is there - just...

If the pulley is massless then the tension T on one side of the pulley is the same T as on the other side, therefore it's the exact same T. But if the pulley is not massless then you have to label one T1, say, and the other T2, even it's the same rope? Same situation if the pulley is...

lambda = h/mv v -> 0 means lambda is -> infinite? So if I have an old pickup truck that moves really slow, its matter wave is huge, right?? So it's now a wave and not a particle?

I caught this in the NY Times: http://community.nytimes.com/comments/www.nytimes.com/2009/06/28/health/research/28cancer.html?sort=oldest&offset=4 The article focuses on cancer research, but the conclusions can be applied to all medical research. As the article correctly pointed out...

Snell's law says n1sin(theta1) = n2sin(theta2) The angle of refraction theta2 can be greater or less than the angle of incidence theta1. That's fairly obvious. My question is if theta2 = theta1 then we don't have an interface (because n1 = n2) so the light is still in the same medium, and...

It looks like (a) is trivial: 1 uC is 10^-6C

I'm sure you can find these in your book: current=charge/time charge=(#electrons)(electron charge) power=(current)(voltage) power=work/time

Thanks for the insight. I was thinking C varies inversely with the capacitor gap d, so if there is no capacitor, then there is no gap, d goes to zero, which means C is infinite... Is this goofy thinking?

I have a quick question about a problem requiring calculating impedance of a circuit where there is no capacitor. The formula for impedance Z is Z=sqrt(R^2 + (Xl - Xc)^2). I am told capacitive reactance Xc = 0 because C = 0 (there is no capacitor in the circuit). But the formula for Xc is Xc...