Recent content by gnarkil

thanks for that, i figured out the y_c to be 75mm. if for instance the t beam was reflected about the x-axis so that it was right side up (looks like a T), would the Ixx be calculated using the Iyy calculations you explained above? And then I would use the parallel axis theorem to find Ixx...

Homework Statement this is really getting confusing, i need to find the second moment of inertia Ixx and Iyy of the upside down beam, please see attachment i've used and studied the other threads relating to the same topic and used wikipedia for the parallel axis theorem but am still...

thanks, i got it correct, it was the frickin exponent!

scrplyr, i tried what you suggested and it was still incorrect E = sigma/2*epsilon_0 = (45*10^-8)/((2)(8.85*10^-12)) = 25423.728 N/C what now?

that may be the case, but it wouldn't make sense to state a problem with such general guidelines, i don't think the problem involves specific dimensions

Homework Statement what is the approx electric field 1cm above a typical sheet of paper with a surface charge density of sigma = 45 nC/m^2?Homework Equations electric field E = sigma/epsilon_0 where epsilon_0 = 8.85*10^-12 E = kq/r^2 where k = 9*10^9, r is distance in meters assume paper...

oh, that simple i got 13.75, but actually it was -13.75

when i made it 17+r the quadratic i would get would be an imaginary number, what am i doing wrong?

thanks it was right

thanks for clarifying how to get the directions, i didn't even think to look at it that way, really cleared up things for me so if i change the direction (signs) of my vectors and re-sum them i should get the answer i am looking for? are my original calculations, ignoring direction, correct...

no, because the field woulf come out of the positive and flow into the negative charge, correct? should it be (17+r) not (17-r), though?

so i should be subtracting vectors then? how do i know which vector component is the positive one, is it based on magnitude?

are you saying the it should be (17+r) instead of (17-r) or asking conceptually? conceptually, if the point is placed a huge distance away, then the electric field would essentially be zero

it seems both my net components are wrong. isn't the problem asking for the net components, therefore wouldn't i just add them regardless of direction?

Homework Statement an electron (charge -e) is at the origin, and a particle of charge +5e is at x = 17nm, find a point (x = ...nm) where the electric field is zero. Homework Equations e = 1.6*10^-19 coulombs electric field E = kq/r^2 where k=9*10^9, q is charge, r is distance The...