Recent content by FatCat0

That fixes the side (thank you), but won't that still result in +infinity as the location of the final image? Edit: Nevermind, I actually redid it and realized that I jumped the gun. That worked, thanks!

I'm studying for the GREs, and I ran across this problem: Object located at x=0 Lens 1 located at x=40cm Lens 2 located at x=70cm (30cm from lens 1) f1 = 20cm f2 = 10cm Both lenses are converging, thin lenses. So I have to find the final image location. The understanding I have of multiple...

Oh, that answer comes out to 3.13926*^-14 by the way. Copied and pasted badly there...

I can and have looked up the constants, but I still can't find any combination of them that makes sense, either in units or in outcome. Using 8.854*10^-12 for E(0) I get this...

I cannot for the life of me figure out what value my professor used for E(0) in this equation (vacuum permittivity). Here's what he wrote down: http://img38.imageshack.us/img38/5663/78976562.jpg It's talking about the first ionization energy of an electron, so I've tried using numbers I...

Ahh, I'll work on it later and come back if I get even more confused. Danke =)

How would you word the average thing? What I meant was sort of what I was saying in post 3; I was looking for an x-value where the area inside the semicircle to the left of it would be equal to the area in the semicircle to the right of it. Both of those equations you posted, Ivy, are a little...

How did you get the that answer? I couldn't think of a way beyond taking y = +- \sqrt{r^{2} - x^{2}}, bounding it to a region of x that formed a semi-circle, integrating that, then trying to find the average. Could you elucidate me as to the method you used? Or possibly point out where I...

Another aside, maybe calling it the average was bad? I need to find the center of mass, which will be along the x-axis. Everything to the right of that point must equal everything to the left, in the system of course. Maybe I'm doing THAT wrong too.

As an aside, even disregarding the +- thing, this doesn't work for a quarter-circle either, since the average couldn't be located 44 times farther from the origin than the shape was.

Homework Statement This is a very simplified physics problem, just need help with the calc part: What x value represents the average of the area for the semicircle with the equation y = +- (r^2 - x^2)^(1/2)? Homework Equations I called the integral A(x) because it represents area...

This is definitely the right equation.

I'll start it for you: f(net) = ma f(friction) = ma mu(k)*g*m = ma mu(k)*g = a Then you can use these two formulas and you should be able to solve it: a = (v(final)-v(initial))/t d = 1/2*a*t^2 + v(initial)tJust a hint: remember that g is negative.

It has to be 11960 W (11.96 kW). I didn't quite get the "u" part when I read through your post, maybe it's some notation I'm unfamiliar with? But just the fact that you have "at = 24-10 = 14." shows that you have vf and vi mixed up in at least one place. at = -14, not +14. The car is slowing...

Ah, okay. I talked to my teacher about this today. Using conservation of energy you still get 11960 (close enough to my previous answer, considering the number of times I rounded in that method). The book's answer was incorrect, and we even figured out why: E = Energy Expended = Ef - Ei = mgh +...