Electric Force/ Electrical Fields

1. Feb 6, 2009

xswtxoj

1. The problem statement, all variables and given/known data

Two electric charges, q1 = +21.3 nC and q2 = +11.0 nC, are located on the x-axis at x
= 0 m and x = 1.00 m, respectively. What is the magnitude of the electric field at the
point x = 0.506 m, y = 0.506 m?

2. Feb 6, 2009

LowlyPion

How would you think to approach the problem?

3. Feb 7, 2009

xswtxoj

21.3+11.0 /1 = .506/.506 ???????????????????????

4. Feb 7, 2009

LowlyPion

Based on what?

5. Feb 7, 2009

LowlyPion

They want you to find the E-field vector at .506,.506.

First calculate the |E1| and |E2| based on the geometric distance to both charges.

Then separate those vectors - they are vectors - into their components.

Then add the x-components and y components separately.

Happily they only want the magnitude of the E-field - |E| - so just use Pythagoras to figure the |E| of the resulting vector.

6. Feb 7, 2009

xswtxoj

theres no angle though, so it would be .506 sin____ and .506cos___ or is it 90 or 180 degrees

7. Feb 7, 2009

LowlyPion

You have the coordinates of the point.

and you know - or should know that a2 + b2 = c2

So ... figure it out.

8. Feb 7, 2009

xswtxoj

.506 sq + .506 sq = 574.69 then sq root = .715,

9. Feb 7, 2009

LowlyPion

It is .715 but your intermediate result is nonsense.

So that's the r for 1 charge.

Now figure the r for the other.

10. Feb 7, 2009

xswtxoj

21.3 sq + 11 sq= 574.7 equals 23.97 after sq rt, then take the 2 r's and add them up and tan y/x?

11. Feb 7, 2009

LowlyPion

We're looking at distances, not charges.

12. Feb 7, 2009

xswtxoj

would it be : E1= ke q1/ r sq? then E2= ke q2/r sq but how would the 2nd r be found would the x= 0, and 1 or 1, 0.506 since it for q2?

13. Feb 7, 2009

LowlyPion

They want you to find the distance from 1,0 to .506,.506 for the second charge. That triangle then is .494,.506.

14. Feb 7, 2009

xswtxoj

once i get r, i solve for e, then once i get both e's do i add them up or leave it as 2 seperate answers?

15. Feb 8, 2009

LowlyPion

Once you get the |E| (magnitude of E) then you must resolve them into their x,y components and add the components - being careful of the signs - and then determine the magnitude of the result.

They want the magnitude of the Total E field at that point.