Coulomb's Law and Final Angle of Dust Cobweb

In summary, a dust cobweb consisting of a single dust ball with a mass of 2.0 x 10^-7g is suspended on a massless string of length 0.42m, connected 0.35m from a wall. The cobweb is drawn towards the wall by another dust ball with an opposite charge of -3.0 x 10^-6C. The question asks for the final angle the cobweb makes with the vertical. Using the equations for electric force and components, the problem becomes a system of two variables (d and θ), making it difficult to solve. A picture of the setup would help in visualizing the problem.
  • #1
leafsfan2
3
0
(I posted this in the wrong section earlier, hopefully i got it right this time...)
1.Homework Statement

A dust cobweb is drawn from an initial vertical position toward a nearby wall by an electrostatic force. Assume the cobweb to be like a single dust ball of mass 2.0 x 10^-7g suspended on a massless string of length 0.42 m connected a horizontal distance of 0.35 m from the wall, as shown below. The tethered dust ball is drawn to the wall by another similar dust ball of opposite charge, -q = -3.0 x 10-6C.
a)what final angle does the cobweb make to the vertical?


2. Homework Equations
Fe = (kq1q2)/d^2



where Fe is the electric force between two objects
K is Coulomb's constant (9.0 x 109 Nm2/C2)
q1 is object 1's electric charge
q2 is object 2's electric charge
d is the distance between centers of charged objects

I tried using components, so:
Ft=Fe/sinθ
And
Fg=Ftcosθ
So I substituted but I end up with two variables (d and θ) so I'm not sure what to do.

(Sorry for any typos and the horrible formatting, I'm posting this off a phone)
 
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  • #2
Could you show a picture showing the dust balls and the forces to make the problem more clear, please?

ehild
 

1. What is Coulomb's Law?

Coulomb's Law is a fundamental law in physics that describes the force between two charged particles. It states that the force between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

2. How is Coulomb's Law calculated?

Coulomb's Law can be calculated using the formula F = k(q1q2)/r^2, where F is the force between the two charges, k is Coulomb's constant (9x10^9 Nm^2/C^2), q1 and q2 are the charges of the particles, and r is the distance between them.

3. What is the final angle in Coulomb's Law?

The final angle in Coulomb's Law refers to the direction of the force between two charged particles. It is calculated using the inverse tangent function, which takes into account the magnitude and direction of the forces acting on the particles.

4. Does Coulomb's Law apply to all types of charged particles?

Yes, Coulomb's Law applies to all types of charged particles, including electrons, protons, and ions. It is a fundamental law in physics and is applicable to all electrically charged objects.

5. How does the final angle change with distance in Coulomb's Law?

The final angle in Coulomb's Law changes with distance based on the inverse square law. As the distance between the two charged particles increases, the force between them decreases and the final angle becomes smaller. This means that the force acts more in the direction of the line connecting the two particles.

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