Posted by **Jim** on Friday, January 11, 2013 at 10:20am.

A point charge +6.7 uC is placed at the origin, and a second charge –3.6 uC is placed in the X - Y plane at (0.40 m , 0.55 m ). Where should a third charge be placed in the plane so that the net force acting on it is zero?

- Physics -
**Elena**, Friday, January 11, 2013 at 4:16pm
tanα=0.55/0.4 =1.375.

α=54⁰

The distance between the charges

d = sqrt(0.4²+0.55²) = 0.68 m

The electric field at the disired point is zero =>

k•q₁/0.68+r)²=k•q₂/r²,

0.86r²-1.36r-0.46=0,

r ={1.36±sqrt(1.85+1.58)}/1.72 = >

r₁=1.867 m , r₂= - 0.28 m (extraneous root)

d+r=0.68+1.867=2.547 m

x=2.547•cos54=1.5 m

y=2.547•sin54=2.06 m.

## Answer This Question

## Related Questions

- Physics - A charge of +2.4 × 10−9 C is placed at the origin, and another ...
- physics - A charge of +2.4 × 10−9 C is placed at the origin, and another ...
- Physics - A 6 µC charge is placed at the origin and a second charge is placed on...
- physics - A point charge Q= 4.60 uC is held fixed at the origin. A second point ...
- physics - Consider a charge of +2.0 C placed at the origin of an X-Y co-...
- physics, math - Part A & B are 0.10m apart. A point charge of +3.0*10^-9C is ...
- Physics - Suppose a charge q is placed at point x = 0, y = 0. A second charge q ...
- physics - A +5.0 µC charge is placed at the origin and a -3.9 µC charge is ...
- Physics - A +5.0 µC charge is placed at the origin and a -3.3 µC charge is ...
- Physics - If one charge (+5 uC) is placed at origin and a second charge of (+7 ...

More Related Questions