A charge of 1 C is at (-2,7,1) and a charge of 2 C is at (8,-1,4) . If both coordinates are in meters, what is the force between the charges?

1 Answer
Jan 31, 2018

F=1.04times10^8 N

Explanation:

Charge 1C placed at (-2,7,1)
Charge 2C placed at (8,-1,4)

Distance between the charges
r=sqrt((x_2-x_1)^2+(y_2-y_1)^2+(z_2-z_1)^2
r=sqrt((8-(-2))^2+((-1)-7)^2+(4-1)^2
r=sqrt((8+2)^2+(-1-7)^2+(4-1)^2)
r=sqrt(10^2+(-8)^2+(3)^2)
r=sqrt(100+64+9)=sqrt(173)

Force between charges
F=(kq_1q_2)/r^2
where k=9times10^9 N-m^2/C^2

F=(9times10^9times1times2)/(sqrt173)^2
F=(18times10^9)/173=0.104times10^9
F=1.04times10^8 N