What do we know has to be TRUE about the action and reaction force below?

the boot kecked the ball which is frictinal force

whichever one it is, it's definitely not one that you included on the list you provided.

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)