TP 19.11

Given:

q₁ = +3.13 x 10^-6 C

q₂ = -4.47 x 10^-6 C

r = 0.255 m

a. Find: F₂₁ -?

F₂₁ = k |q₁||q₂|/r²

F₂₁ = (8.99 x 10⁹ N-m²/C²) |+3.13 x 10^-6 C||-4.47 x 10^-6 C|/(0.255)²

F₂₁ = 1.93 N

b. The same as: Third Newton's Law.