What is the net electric force on the charge at the origin?

[sushi362]

Homework Statement

Consider three charges in a triangle as shown.

1. What is the net electric force on the charge at the origin?

2. What is the direction of this force(between -180 and 180)?

3. What is the magnitude of the net electric field at the position of the charge at the origin?

4. What is the direction of the net electric field?

Homework Equations

E = Kc * Q/r^2

The Attempt at a Solution

I solved part 1, to be 2.5*10^-6
part 2 is -102.38

i have no clue what to do for part 3.
once i figure that out, i should be able to do part 4.

 

[tms]

You listed the equation for the electric field, why not use it?

 

[Stealth849]

Net electric field is found form the electric field created by the charges.

Electric field is also a vector quantity which can be summed.

E = kq/r²

You should be able to find the electric field for each charge and through vector addition, find the net field.

Also consider: The charge at the origin does have a field, but if a test charge is at the origin too, (directly in the middle of the charge at the origin), will the test charge be affected by the field of the charge at the origin?

 

[sushi362]

You listed the equation for the electric field, why not use it?

so #3 is the same as #1?

i used the equation to calculate the e field for the 2 points: origin to the right of the origin, and origin to south of origin. then i took the square root of the squares of those values, and got part 1 again?

 

[tms]

so #3 is the same as #1?

No. #1 wants the force while #3 wants the field. They aren't the same. The equation you wrote down under "Relevant equations" is for the field.

Show us your calculations.