Question

The figure shows four electrical charges located at the corners of a rectangle. Like charges, you will recall, repel each other while opposite charges attract. Charge B exerts a repulsive force (directly away from B) on charge A of 3.0 . Charge C exerts an attractive force (directly toward C) on charge A of 6.0 . Finally, charge D exerts an attractive force of 2.0 on charge A.

141cm
Figure: A--------B
100cm | |
| |
C--------D

(1) Assuming that forces are vectors, what is the magnitude of the net force exerted on charge A?
(2) What is the direction of the net force exerted on charge A? (degrees counterclockwise to the left)

Answer 1

On A
to the left, 3,
downward, 6
the diagonal can be then
downward (2*costheta=2*1/sqrt5)
and to the right 2 sinTheta=2*sqrt2/sqrt5

check those, the trig functions are a result of the dimensions.

Finally, add the downward and horizontal as vectors.