phYsics

posted by .

Two identical objects each hold a net charge of q = 8e. If the gravitational force between the two objects exactly cancels the electrostatic force between the objects, what is the mass of each object?
Where G: 6.67E-11
Ke=8.99E9

I know the equation is
m=sqrt(ke*q^2/G)
yet when I plug everything in I got 2.52E11 which is incorrect.
Please help, I'm frustrated...

  • phYsics -

    G M^2/R^ = Ke 64 e^2/R^2

    M^2 = 64 Ke e^2/G
    M = 8e sqrt(Ke/G)

    You seem to be using the right formula, but I get a different numerical answer.

    Are you sure you are using the right electron charge (e)?

  • phYsics -

    Oh, you mean the 'e' in the 8e might stand for 8 times electron charge of 1.60217646E-19 coulombs? I was doing it as 8 times e(the mathematical constant 2.71828183)

  • phYsics -

    Yes, e is the electron charge. You are comparing electrostatic and gravitational forces

  • phYsics -

    Thank you! I should have known that, guess its getting late :)

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics HELP PLEASE

    two spherical objects are separated by a distance of 9x10^-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the addition …
  2. physics

    Two spherical objects are separated by a distance of 2.41 x 10-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the addition …
  3. Physics

    In mathematical language, Newton's Law of Gravity expresses the force of gravity, F, between two objects in the following way: F= (GMm)/r^2 where M is the mass of one object, m is the mass of the other object, r is the distance between …
  4. physics

    Two spherical objects are separated by a distance of 1.41 × 10^-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the …
  5. Physics**

    1) Assume that you have two objects one with a mass of 10 kg and the other with a mass of 15 kg each with a charge of +3.0x10^-6 C and separated by a distance of 2 m. What is the electric force that these objects exert on one another?
  6. Physics***

    1) Assume that you have two objects one with a mass of 10 kg and the other with a mass of 15 kg each with a charge of +3.0x10^-6 C and separated by a distance of 2 m. What is the electric force that these objects exert on one another?
  7. Physics

    In a vacuum, two particles have charges of q1 and q2, where q1 = +3.8C. They are separated by a distance of 0.37 m, and particle 1 experiences an attractive force of 4.7 N. What is the value of q2, with its sign?
  8. physics

    Two spherical objects are separated by a distance of 1.53 × 10-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the …
  9. Physics

    Two spherical objects are separated by a distance of 2.97 × 10-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the …
  10. Physics

    A 145-kg object and a 445-kg object are separated by 3.90 m. (a) Find the magnitude of the net gravitational force exerted by these objects on a 34.0-kg object placed midway between them. (N) (b) At what position (other than an infinitely …

More Similar Questions