Recent content by Dart82

Homework Statement A cat is standing 1m in front of a mirror. a virtual image is formed 10.0m behind the mirror. what is the radius of curvature for the mirror? Homework Equations 1/f = (1/do)+(1/di) f=+/-(1/2)*R The Attempt at a Solution (1/1m + 1/10m)^-1 = .909 .909*2 = 1.82...

I'm not sure, but i know if i only calculate the field for the loop i get 5.7 gauss which is not the correct answer.

Homework Statement The radius of a single coil of wire is 0.22m. It carries a 200 A current that flows clockwise. A long, straight wire carrying a current of 310 A toward the right is located 0.05m from the edge of the coil. What is the value of the magnetic field at the center of the coil...

got it right finally. thanks

how does this look? lambda = R [(1/infinity)-(1/1^2)]^-1 lambda= 9.12x10^-8 meters or 91.2 nm

Homework Statement Is it possible to use electromagnetic radiation to ionize atoms. To do so, the atoms must absorb the radiation, the photons of which must have enough energy to remove an electron from an atom. What is the longest radiation wavelength (nm) that can be used to ionize the...

yes i am right now...

got it... no photoelectric effect.

ok i see what you are saying. i guess because the only other place i have seen the eV is in the photoelectric effect problems. i have read my notes and the section in my book concerning the de Broglie Wavelength (which there were no examples problems given). consequently, i am having a tough...

sorry, i misunderstood what you had said about the dimensions of the beam. i think i need to take a break and try this one again later. 5 hours of Physics homework has tweaked my brain a bit too much. thanks for your help Dick.

Ok, i got the right answer but i only understand about 90% of what i did to get it. According the Photo. effect: h*f - W = KE ...so then h*f - W = (1/2)mv^2 I guess my only question is where did the h and f disappear to?

well...i guess because i don't understand how the work function can just be set to equal the kinetic energy. how is it that the hf can just be dropped from the photoelectric equation? I sure do wish my teacher would have spent some more time on this stuff - it seems like he just left out half...

Do i add the area of the laser beam to the energy of each photon (E)? this is so frustrating...

Dick - i wish i could tell you that it makes perfect sense now, but I'm still a bit confused here. When you say no relativity what exactly does that mean?

Homework Statement Find the de Broglie wavelength of a 7.0 eV electron.Homework Equations de Broglie wavelength = h/p = h/(mv) Photoelectric effect equation (not 100% sure) The Attempt at a Solution i need to solve for v in de Broglie's equation so i can find the wavelength. i know the mass of...