Posted by **Megan** on Thursday, April 5, 2012 at 1:33pm.

Two spheres with charges of 4.00nC and 3.00nC are placed 0.500m apart. At what point between the two charges must the third charge of 2.00cN be placed so that the net electrostatic force acting on this charge is zero?

- physics -
**Elena**, Thursday, April 5, 2012 at 1:51pm
k q1 q3/x^2 = k q2 q3/(d-x)^2

q1 q3 (d-x)^2 = k q2 q3 x^2

Solve for x

- physics -
**Elena**, Thursday, April 5, 2012 at 1:55pm
The second line

q1 q3 (d-x)^2 = q2 q3 x^2

- physics -
**Megan**, Thursday, April 5, 2012 at 2:26pm
Elena, for some reason I'm getting an answer of -3

(8.00 x 10^-12) x (d-x)^2 = (6.00 x 10^-12) x (x^2)

(d-x)^2/x^2 = 7.5 x 10^-1

(d-x)(d-x)/x^2 = 7.50 x 10^-1

x^2-x+0.25/x^2= 7.50 x 10^-1

then I get x = -3

Can you help! I'm not sure where i am going wrong.

- physics -
**Elena**, Thursday, April 5, 2012 at 3:54pm
q1 (d-x)^2 = q2 x^2

410^-9(d-x)^2 = 310^-9x^2

4(d^2 - 2dx + x^2) = 3x^2,

x^2 - 4x + 1 = 0

x =2 ą sqrt(4-1) =2 ą 1.73.

x1 = 0.27 m, x2 =3.73m (falls out)

## Answer This Question

## Related Questions

- physic - two point charges are placed on the x axis as follows: charge q1 +4....
- science - Two point charges are placed on the x-axis a follows: charge q1= +4....
- Physics - A charge q1 = 5.00nC is placed at the origin of an xy-coordinate ...
- physics - Two point charges are placed on the x axis as follows: Charge q1= +4....
- Physics - Two point charges are located on the y axis as follows: charge q1 = -2...
- physics - Two point charges are placed on the x axis. (Figure 1) The first ...
- physics - charge q1=+4.00nc is located at x=0.200m, and q2 =+5.00nc is at x=-0....
- Physics - Two point charges, one of +3.00 10-5 C and the other -5.00 10-5 C are ...
- physic - two point charges are placed on the x axis as follows: charge q1 = +4....
- Physics - A)When point charges q1 = +1.5 ěC and q2 = +5.7 ěC are brought near ...

More Related Questions