Charge and Coulombs Law Interview Questions 

A point charge of 5.00 x10^(-6) is on the y axis at y =3.00 cm and a second point charge of -5.00 x10^(-6) is on the y axis at y= -3.00 cm. Find the elctric force on a point charge of 2.00 x10^(-6) on the x axis at x= 8.00 cm

There are two charges q1= 3.5 c and q2 = ?? separated 4.0m. A third charge of 5.5c, is placed 1.0m away from q1. If the net electric force on this third charge is zero, what is the charge of q2?

I have two problems that I really can't figure out:

1. Two charges attract each other with a force of 1.0 N. What will be the force if the distance between them is reduced to one-ninth of its original value?

2. Two very small spheres are initially neutral and separated by a distance of 0.50 m. Suppose that 2.50 x 10^13 electrons are removed from one sphere and placed on the other. What is the magnitude of the electrostatic force that acts on each sphere?

I know that I need to use Coulomb's law somehow to solve these but I'm not sure where to begin or how to set it up. Any help on how to solve either of these problems would be greatly appreciated.

1.Write an explaination based on the propertites of charges, forces and insulators on the test by picking up smalll pieces of paper(by temporary charging) for both positive and negative charged objects.
2. define electric field in terms of the electrostatic force on a test charge. using exapmes, briefly explain why it is sometimes usefyl in electrostatics problems to calculate the electric field as opposed to working directly with coulombs's law.

Two small aluminum spheres, each having mass 0.0250kg, are separated by 80.0cm. a) How many electrons does each sphere contain? (the atomic mass of aluminum is 26.982g/mol, and its atomic number is 13.) b) How many electrons would have to be removed from one sphere and added to the other to cause an attraction force between the spheres of magnitude 1.00 x 10^4 N (roughly one ton)? Assume that the spheres may be treated as point charges. c) What fraction of all the electrons in each sphere does this represent?

The safe limit for beryllium in air is 2.0 X 10^ -6 g/m^3, making beryllium one of the most toxic elements. The charge on all electrons in the Be contained in 1 m^3 of air at the safe level is about 0.085 C. Suppose this charge is placed 2.00 km from a second charge. Calculate the value of the second charge if the magnitude of the electric force between the two charges is 8.64 X 10^-8 N.

Please help me and show your work! Thank you!

PHYSICS: Can you solve this Coulomb's Law problem? please do show your solutions:
3 point charges are arranged on a line.
q1 (?nC) y=+2cm;
q2 (-3.00 nC) y=+4.00cm;
q3 (+5.00nC) x=0;
What is q1 (magnitude and sign) if the net force on q3 is zero?

5. Would it be necessary for a charged object to actually touch the leaves of an electroscope for the leaves to diverge? Defend your answer.
6. If a glass rod that is rubbed with a plastic dry cleaner's bag acquires a certain charge, why does the plastic bag have exactly the same amount of opposite charge?
7. Why is a good conductor of electricity also a good conductor of heat?
8. Explain how an object that is electrically neutral can be attracted to an object that is charged.
9. If electrons were positive and protons negative, would Coulomb's law be written thesame or differently?
10. The five thousand billion billion freely moving electrons in a penny repel one another Why don't they fly out of the penny?

Kalyan Ramji Sain, of India, had a msutache that measure 3.39 m from end to end in 1993. Suppose two charges, q and 3q, are placed 3.39 m apart. If the magnitude of the electric force between the charges is 2.4 X 10^ -6 N, what is the value of q?

Please help me and show your work! Thank you!!!

A charged particle A exerts a force of 2.62µN to the right on charges particles B when the particles are 13.7 mm apart. Particle B moves straight away from A to make the distance between them 17.7 mm. What vecot force does particle B then exert on A?

I have no idea how to approach this problem. Any guidance would be appreciated.

The drawing shows three point charges fixed in place. The charge at the coordinate origin has a value of q1 = +9.00 µC; the other two have identical magnitudes, but opposite signs: q2 = -5.50 µC and q3 = +5.50 µC.

http://www.webassign.net/CJ/p18-18.gif


(a) Determine the net force (magnitude and direction) exerted on q1 by the other two charges. magnitude N
direction ° (measured counter clockwise from the x-axis)

(b) If q1 had a mass of 1.20 g and it were free to move, what would be its acceleration?

Given Coulomb's Law, which of the following statements are true?
1. If the radius tripled the force would be 1/9 of the original force
2. If Q1 increased from a value of 1 to a value of 2, force would double
3. If the radius doubled, the force would be ¼ as strong
4. If the radius tripled, the force would triple
5. If both charges doubled, the force would double.
6. If the radius doubled, the force would increase by 4

Ok, so here's the basic problem:

There is a hollow ring that has a positively charged top half and a negatively charged bottom half. In the center there is a point (at (0,0)). Now, I, in symbolic terms, need to know what the electric field would be at this point p.

I've used coulomb's law to solve but have fouled up somewhere. I will include my work and the actual answer.

E = 2 * sum (from -pi to pi) k q / r^2 * sin (theta) <---To give just the y component

E = 2 [ integral (from -pi to pi) (k q / r^2 * sin (theta) d(theta) )]

E = 2 ( k q / r^2 * 2)

E = 4 k q / r^2 = q / (pi * epsilon * r^2)

The answer in the book is: q / (pi^2 * epsilon * r^2).

Help?

We have learned that the magnitude of the acceleration due to gravity of an object near the surface of the earth is 10 meters/second^2. The radius of the earth is about 6400 kilometers (). Assume that the earth has a charge of 1 Coulomb. What is the size of the force that would be exerted on an object at the earth’s surface that also had a charge of 1 Coulomb? (Take the constant in Coulomb’s law to be 9*10^9 with the appropriate units.) If the object has a mass of 1 kg, what would its acceleration due to the Coulomb force be?

In a vacuum, two particles have charges of q1 and q2, where q1 = +3.5 µC. They are separated by a distance of 0.26 m, and particle 1 experiences an attractive force of F1=3.5 N.

What is the force acting on the second particle F2 (magnitude and sign)?