Finding the net electrostatic force on particle 1, triangle

In summary, Mr. Coffee suggested that you use trigonometry to find the y-component of the force between particles 1 and 2.
  • #1
mr_coffee
1,629
1
Hello everyone, Did I do the 2nd part of this problem correct? Part B. I boxed in the answer, i think it will just be easier by showing you my drawing so here is the picture -> http://img221.imageshack.us/img221/9340/phsyicss9lb.jpg
thanks!
 
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  • #2
I suggest that you recheck your arithmetic for part a. The method you used for part b looks OK (it's a bit hard to follow), but it's not the easiest way to get the answer. (You didn't take full advantage of the symmetry of the geometry.)
 
  • #3
thanks for the reply but I don't see how part A is wrong...
F = [k(q1)(q2)]/r^2;
F = [9.9E9*(45.0E-6)^2]/(2.70)^2 = 2.75 N
 
  • #4
The Coulomb constant (k) is about 9.0 E9, not 9.9 E9.
 
  • #5
thanks a lot that woulda sucked!
 
  • #6
for the second part, i don't even think it's necessary to use trigonometry.

consider point 3 at the origin in R2. put particles 1 and 2 at the appropriate positions in quadrant's 3 & 4. draw your force vectors for each of the forces. add them visually -- they interfere constructively directly in the +y direction. it looks to me like you'd just have to multiply your answer from a by 2, due to the geometry.

i think it's right and a lot easier than breaking it down into components, but it looks fine barring the oofpez business.
 
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  • #7
teclo said:
consider point 3 at the origin in R2. put particles 1 and 2 at the appropriate positions in quadrant's 3 & 4. draw your force vectors for each of the forces. add them visually -- they interfere constructively directly in the +y direction. it looks to me like you'd just have to multiply your answer from a by 2, due to the geometry.
You would multiply the y-component by 2 to get the answer. But you'd still have to use some trig to find the y-component. (The answer to part a is the full force between two charges, not the y-component.)

Note to mr_coffee: This is the approach I would use, since it takes advantage of the symmetry of the problem.
 
  • #8
(The answer to part a is the full force between two charges, not the y-component.)

So part A isn't correct? I don't see why I would need to break up part A into components if its a straight line. F = [(9E9)(45.0E-6)^2]/(2.70m)^2 = 2.5N
The way I did my part B isn't it also correct though, even though I didn't do it the best of ways? I got a final answer of 4.33N
 
  • #9
Your solutions are perfectly OK. My only point was that there's an easier way to get part b.
 
  • #10
Oh alright, thanks for the help and i'll keep that in mind the next time! :biggrin:
 

1. How is the net electrostatic force on particle 1 in a triangle calculated?

The net electrostatic force on particle 1 in a triangle is calculated by adding together the individual electrostatic forces between particle 1 and the other two particles in the triangle. This can be done by using Coulomb's Law, which states that the force is equal to the product of the charges divided by the square of the distance between them.

2. What factors affect the magnitude of the net electrostatic force on particle 1 in a triangle?

The magnitude of the net electrostatic force on particle 1 in a triangle is affected by the charges of the particles and the distance between them. The force increases as the charges of the particles increase, and decreases as the distance between them increases.

3. Can the net electrostatic force on particle 1 in a triangle be negative?

Yes, the net electrostatic force on particle 1 in a triangle can be negative. This means that the force is acting in the opposite direction of the positive direction, which is typically defined as the direction of the force on a positive charge.

4. How does the position of particle 1 affect the net electrostatic force in a triangle?

The position of particle 1 in a triangle does not affect the net electrostatic force. This is because the net force is calculated by considering the distances between particles, not their specific positions within the triangle.

5. Can the net electrostatic force on particle 1 in a triangle ever be zero?

Yes, the net electrostatic force on particle 1 in a triangle can be zero if the charges of the other particles are equal and they are positioned symmetrically around particle 1. In this case, the forces between particle 1 and the other particles cancel out, resulting in a net force of zero.

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