Three point charges are on the x axis: −6 µC at −3 m, 7 µC at the origin, and −5 µC at 3 m.

Question

Find the force on the first charge.
The value of the Coulomb constant is
8.98755 × 10^9 N · m^2/C^2.

Answer 1

k=8.98755 × 10^9 =9•10 ⁹N • m^2/C^2.

q1=−6 µC, q2 =7 µC, q3 =-5 µC

F12=k•q1•q2/r1²=9•10⁹•6•10⁻⁶•7•10⁻⁶/9 =….
(to the right)
F13=k•q1•q3/r2²=9•10⁹•6•10⁻⁶•5•10⁻⁶/36 =…
(to the left)
F=F12-F13=…
(to the right)