Hi, we are in Physics 202 and working on a few problems that we cant solve. We had a BUNCH of people working together and cant seem to get any of these.

 

Q1- Consider a parallel plate capacitor with area A, and seperation D. A large insulation sheet is inserted between the plates. It has dialectric constant K.

 

1) What force acts on the sheet if the voltage is kept constant?

2) What force acts on the sheet if the charge is kept constant?

3) How does the sheet affect the energy of the capacitor for 1)?

4) How does the sheet affect the energy of the capacitor of 2)?

 

Q2- 2 metal plates of area A form a capacitor. The bottom plate does now move but the top plate is connected to a spring where as the plates pull together the spring stretched.

------Top mount (doesnt move)

- Spring

-

---- Upperplate

---- Bottom plate (doesnt move)

 

What is the maximum voltage between the plates that causes them to not touch? qE=kx???

 

Q3- Consider a cube made from 1 ohm resistors on each side.

 

a) What is the equivalent resistance between 2 end points of the body diagonal of the cube arrangement.

 

b)What would the equivalent resistance of a 1d "cube"?

c)Same but for a 2d "cube".

d)Same but for a 4d "cube". Hypercube.

 

 

---------------

 

Weve been working on these for quite awhile and arent getting far. Its due tuesday so any help would be much appreciated. We have some "answers" but some may just be last ditch efforts to get partial credit.. PLEASE HELP!!

 

Thanks!

RC,

 

The rules of this forum don't allow members to post solutions to your problems directly.

 

What members of this forum will do is help guide you along the way, will point out mistakes where they seem them, etc.

 

Basically, what I am getting at, is please post what work you and your group has done so far, and the forum may be able to help nudge you on the correct path, and correct mistakes where we see them.

Alright will do next time.

 

Anyways, we figured out the hypercube part.

 

Its kind of hard to write out what we have...

the easiest thing to do is calculate flux through your capacitor and then make sure you have enough pencils becasue it takes alot of writing to calculate this "Integrate with respect to ¥" if your teacher hasnt tought you this i would recommend quiting at life.

For which problem are you talking about? If its the spring capacitor one, we think we got the answer. Answered it from an energy standpoint. The original electric potential energy of the capacitor is equal to the springs potential energy at the end. Were pretty confident with what we got.

 

So it comes down to just the dialectric one. He asks what forces act on the sheet. Isnt there only one, the force between each plate of the capacitor and the polarized dialectric sheet?