Find the net force on q3. Include the
direction (+ or -).
(Unit = N) PLS HELP!

Explanation:

First of all we shall find out net  electric field at q₃ due to both of the remaining charges .

electric field due to charge Q = k Q / r² where k = 9 x 10⁹ Q is amount of charge and r is distance of point

electric field due to charge 105 x 10⁻⁶ C

= 9 x 10⁹ x 105 x 10⁻⁶ / .95²

= 1.047 x 10⁶ N/C  .

It will act away from q₂

electric field due to charge 53 x 10⁻⁶ C

= 9 x 10⁹ x 53 x 10⁻⁶ /( .5+.95)²

= 0.227  x 10⁶ N/C  .

It will act towards   q₁

These fields are in opposite direction so

net field E = 0.82 x 10⁶ N/C.

It will act away from  q₂ .

Force on q₃ due to net field

= q₃ E

= 88 x 10⁻⁶ x 0.82 x 10⁶

= 72.16 N

The direction of this field will be towards q₂ because force on negative charge in a field is always in a direction opposite to the direction of the field.