Three tiny charged metal balls are arranged on a straight line. The middle ball is positively charged and the two outside balls are negatively charged. The two outside balls are separated by 20 cm and the middle ball is exactly halfway in between. (HINT: Draw a picture; in your picture, the distance between the two outermost balls should be 20 cm.) The absolute value of the charge on each ball is the same, 1.12 μCoulombs (the meaning of μ, which is read as "micro", is 10-6). Give your answers in newtons.
(a) What is the magnitude of the attractive force on either outside ball due ONLY to the positively-charged middle ball? N
(b) What is the magnitude of the repulsive force on either outside ball due ONLY to the other outside ball? N
(c) What is the magnitude of the net force on either outside ball? N