Physics-a wool cloth and balloon-simple but i can't get it!!?

Question

A- A balloon is rubbed with a wool glove. The two items attract one another with a force of strength 0.6 N when they are 1 cm apart. If they have equal but opposite charges, what is the magnitude of the charge?

B-How many electrons were transferred?

Answer 1

I assume that the glove is much bigger then 1cm. Therefore you can not use the equation for point charges. You'll need to know the surface area of the glove.

But maybe your teacher isn't aware of that.

The equation for the force between two parallel plates is this

F=q^2/(2* A * e0)

q is the charge, A is the area and e0 is the electric constant

e0=8.85*10^-12 C^2/(N*m^2)

Answer 2

A.

kQq/r^2 = 0.6 N

Q = q

kq^2/r^2= 0.6

q^2= 0.6r^2k

q=sqrt(0.6kr^2)

B.

Divide the charge by the charge of a single electron and you'll have the number transfered.

Edit:

I hate when arrogant people try to make themselves look smart.  First of all, to find the EXACT force, you must integrate the force over the surface of both objects.  This is extremely difficult because force is a vector.

dF=k(dq1)(dq2)/dr^2

Each dF has its own direction which must be accounted for when integrating.  And in case you didn't notice, this equation absolutely would require a computer or a lot of spare time.

Do yourself a favor and try not coming off as an arrogant s*****k in the future.  And if that's what you intend to do, make sure you're at least correct.