A charge of -8µpC and a charge of +6µpC are placed so that they exert a force of 8.4 N on each other. How far apart are the charges? Compare the electrical and gravitational forces.

Question

drawn diagram is needed with the solution, thank you

Answer 1

1)To solve the problem, we will use Coulomb's Law in the form F = k q₁q₂ / d²,

where F = 8,4 N is the force between the charges,

k =9x10⁹ Nm²/C² - constant in SI units,

q₁ = -8 μC = - 8x10^-6 C the first charge

q₂ = 6 μC = 6x10^-6 C the second charge

d - distance between the charges.

From the formula for force, we can get d = √k q₁q₂ / F

Let's plug in to this formula the values of the variables:

d = √9x10⁹x8x10^-6x6x10^-6/8,4 = 0.23 (m)

2) I believe that it is a separate question about the comparison of electrical and gravitational forces. Ok, let's give it a try.

1. both forces are central, they are inversely proportional to the square of the distance
2. gravitational force is long-range and electrical - is short-range force
3. gravitational force only a force of attraction, but electrical force could be attractive or repulsive
4. we cannot shield ourselves from the gravitational force, but it is easy to shield electrical force using the metal grounded shield.
5. for two given elementary particles the electrical force is approximately 10 ³⁸ times stronger than gravitational.

Hope this was helpful for you. Good luck!

Note: sorry, but the software we use is not yet have a feature to show diagrams. In my opinion they are not helpful for this problem.