A charge of -2 C is at (-2 , 1 ) and a charge of -1 C is at (5, 3) . If both coordinates are in meters, what is the force between the charges?

1 Answer
Jan 27, 2017

According to Coulumbs Law: mathbf F = (k Q_1Q_2)/(abs(\mathbf r_1 - \mathbf r_2)^2) mathbf e_(r_1 - r_2)

Coulumb's Constant is k approx 8.99×10^9 Nm^2/C^2

The magnitude of the force evaluates as:

| mathbf F |= ( 8.99×10^9 * (-2) * (-1))/(abs(((5),(3)) - ((3),(1)))^2) = 2.2475 * 10^9 N

....with abs(\mathbf r_1 - \mathbf r_2)^2 = 8.

[The answer may look big but note that a charge of "only" 1C is a lot of charge.]