diff-charged particles (easy)

[psyclones]

 

Hi,

Can you assist with the following (refer to attachment). I've sketched out how I think the particles will behave, given a -2Q particle interacts with each of the +ve particles (in turn).

But my problem is; if the particles of opposite charge are touching. The attractive force become infinite.

F = k (q(1). q(2) )/ r^2

r --> 0, F --> inf.

Do the particles move? the problem states that they're fixed(??)

Your thoughts.
Any assistance will me much appreciated.

Just add to that.
To calculate the applied charges, I'd have to use a field equ, F = E/q, where E is the electric field as a result of the other particles acting on +3Q,

But how do I (or would you) formulate a field equation for all particles?

hw-problem.pdf

[swansont]

In the part that asks for the force, the spheres are not touching. The second question, where the spheres touch, does not ask you for the force. It's asking for the charge on the spheres after contact. What happens to charge after conductors come into contact?

[psyclones]

ok, I see what your saying, the metal sphere's don't have static charges?

[swansont]

ok, I see what your saying, the metal sphere's don't have static charges?

 

 

They are conducting. So if they touch, what happens?

[psyclones]

If they conduct, charges (electrons) are transfered. (please refer to attach). What am I doing wrong though, I still can't get a coherant answer?

 

But how can a particle feel the charge of another particle without calculating the Force or Field btw them? and without knowing the distance...

Thanks for you help. If the average charge of each pair is calculated as so;

Particle R + -2Q = -1/2Q (averaged)
Particle S - 1/2Q = +3/4Q (averaged)
Particle T + 3/4Q = +15/8Q (averaged)

Ans: +15/8Q

Therefore force & fields aren’t included in this problem.

hw-problem2.pdf

[Sensei]

Conductance here is not needed.

If we charge glass rod by rubbing, it gains electrons on surface.

Then we can discharge it by touching and the thing we touched receives part of electrons.

 

In Van Der Graaf high voltage generator, electrons are transported by silk/rubber.