Charge and Coulombs Law Interview Questions 

Coulomb's Law states:

(a) that like charges repel and unlike charges attract
(b)the direction of the electric force field
(c) how electrostatic force depends on the charges and the distance between them
(d) the relationship between the magnitude and direction on the electric force field.

this is the question in a nutshell...
charge q1=3.00*10^-6C is at the origin
charge q2=5.00*10^-6C is at rest at x=2.00m
find the magnitude and direction of the electric force on charge q2.

i was able to get the magnitude F=3.37*10^-2N, but i'm stuck on how to find the direction.

thanks in advance!

Two small silver spheres, each with a mass of
100 g, are separated by 0.48 m. The num-
ber of electrons per atom of silver is 47, and
the number of atoms per gram is Avogadro's
number divided by the molar mass of silver,
107.87 g/mol.

The Coulomb constant is 8.9875 x
109 N x m^2/C^2 and the Avogadro's number
is 6.02214 x 10^23 mol^-1.

Calculate the fraction of the electrons in
one sphere that must be transferred to the
other in order to produce an attractive force
of 10000 N (about a ton) between the spheres

can anyone help with this problem? the professor explained force between two charges with coulomb's law and threw this question at me to do. And I have no clue how to even start this.

thank you for your help

1. An airplane is flying through a thundercloud at a height of 2000 m. (This is a very dangerous thing to do because of updrafts, turbulence, and the possibility of electric discharge.)
If there are charge concentrations of +43.0 C at height 2800 m within the cloud and -43.0 C at height 1000 m, what is the magnitude of the electric field E at the aircraft?
Round your answer to three significant figures. Take the Coulomb constant to be 8.99x10^9.


2. In a particular television picture tube, the measured beam current is 51microA How many electrons strike the screen every second?
Round your answer to three significant figures. Give your answer in scientific notation. Elementary change is 1.60x10^-19.


3. A person notices a mild shock if the current along a path through the thumb and index finger exceeds 77 microAmps Compare the maximum allowable voltage without shock across the thumb and index finger with a dry-skin resistance of 4.5x10^5 ohms and a wet-skin resistance of 2200 ohms


4. A battery having an emf of 9.70V delivers 104mA when connected to a 82.0 ohm load. Determine the internal resistance of the battery. Round your answer to three significant figures.


If you can help me out that would be great!

The salt will separate when it enters the water so you will have Na+ and Cl-

Because water is a polar molecule (the oxygen is more electronegative than the hydrogens) the Na+ will become attracted to the oxygen while the Cl- will move toward the hydrogens.

At the same time, the Na+ will repel away from the hydrogens while the Cl- will repel from the oxygen.

Two identical small metal spheres with q1>0 and |q1| > |q2| attract each other with a force of magnitude 55.4 mN. They are separated by a distance of 3.94 m. The radius of each sphere is 40 micro-Newtons.

The spheres are then brought together until they are touching. At this point, the spheres are in electrical contact so that the charges can move from one sphere to the other until both spheres have the same final charge, q.

After the charges on the spheres have come to equilibrium, the spheres are moved so that they are 3.94 m apart again. Now the spheres repel each other with a force of magnitude 6.648 mN.

The Coulomb constant k is 8.98755x10^9 N*m^2/C^2.

What is the initial charge q1 on the first sphere?

Relevant equations:
F = k*|q1*q2|/r^2

I can get as far as figuring out the TOTAL initial charge of q1*q2. That's easy: |q1*q2| = F*r^2/k. What stumps me is how I can figure out what only ONE of them is -- the problem states that they're not equal, but I can't for the life of me figure out how to get an exact number. I'm guessing it has something to do with the fact that first, they are attracted to one another and then they repel after reaching equilibrium.

The Sun generates most of its light through a series of nuclear reactions called the proton-proton chain. The overall process of these nuclear reactions can be summarized as 4 1H ? 2He + 2? + 2? + 2? where ? is a small neutral particle called a neutrino, and ? is a photon (a particle of light), which is also neutral. The pre-subscripts on the element symbols H (hydrogen) and He (helium) indicate the number of protons in the nucleus of each element. What is the charge of the unknown entity "?" ?

The choices of charge are from the following list:

+2e, +e, 0, -e, -2e