Recent content by CaneAA

I did draw a diagram--I just don't know what "do" or "di" would be in this case, since I can't figure out how to incorporate the person's distance from the mirror. I'm guessing that the person must factor into the "do" or "di" measurement somehow. And I don't see how the magnification would...

Homework Statement A woman stands between a vertical mirror, 0.5 meter tall, and a distant tree whose height is H. she is 1.0 m from the mirror and the tree is 9.0 m from the mirror. If she sees the tree just fill the mirror, what is H? Homework Equations m = (hi/ho)/(-di/do) hi =...

I see, thank you. But how do you know they're referring to power and not energy? They don't mention power or rate of energy radiated.

Homework Statement By what factor does the radiated energy increase when a blackbody changes temperatures from 100K to 1000K a) 100 b) 6600 c) 1 x 10^ 4 <--- marked as the correct answer on the key. d) 5.7 x 10^4 e) 1 x 10^6 Homework Equations 1) f(peak) = 5.88x10^10*T 2) E =...

Thank you :)

I would appreciate some clarification on working with lenses and virtual objects (when the object distance do is negative). I'm not sure what happens when the do is negative and you get a positive value for di. On which side of the lens does the image go? Normally, for a lens, if di is...

I don't understand what you're trying to tell me. :confused: For part A, why do you say it's perpendicular? I see that the B and I are on separate planes, but isn't the angle between the current and the magnetic field 72? *look at my (beautiful) hand-drawing. The only other option I see for...

Hi Tiny-tim, thanks for your reply. So for part A, the angle would be 72, but the force would be directed straight into the page (-z direction). Is this correct? For part B, I'm having a hard time following your answer since my physics class doesn't go into cross product--we find direction...

Homework Statement A high-voltage power lines carries a current of 110 A at a location where the Earth's magnetic field has a magnitude of .59 G and points to the north, 72 degrees below the horizontal. Find the direction and magnitude of the magnetic force exerted on a 250-m length of wire...

Thank you! :smile:

Thank you, that made sense. :)

I am having a difficult time determining the sign of work in electrostatic problems. I'm attempting to reason out a general rule based on the given examples in my book and to relate it to work done by gravity--but I'm getting two contradictory observations. I don't know if maybe there are...

Calculate the work done by a 3.0V battery as it charges a 7.8-microFarad capacitor in the flash unit of a camera. The Attempt at a Solution I realize that Work = Energy. And by using U = .5CV^2 I can easily come up with the answer. But when I first started doing the problem, I tried doing it...