A charge of #-2 C# is at #(1,4 )# and a charge of #-1 C# is at #(12 ,-5) #. If both coordinates are in meters, what is the force between the charges?

1 Answer
Jul 11, 2016

Answer:

#8.9*10^7N#

Explanation:

Distance between charges:

#|vec(r)| = sqrt(Deltax^2+Deltay^2) = sqrt(11^2+9^2) = sqrt(202)#

Using Coulomb's law:

#vec(F) = (Q_1Q_2)/(4piepsilon_0r^2)hat(r)#

The direction of the force is along the line connecting the charges radially and we will have #F_(12) = -F_(21)# anyway so the direction is not critical. We will find the magnitude now:

#|vec(F)| = 1/(4piepsilon_0)((-2)(-1))/(sqrt(202))^2 = 1/(2piepsilon_0(202)) = 8.9*10^7N#