The net force on the quarterback when he is hit by two linebackers running eastwards is 255N.
Force is a vector quantity, we must recall that if two forces act in the same direction, we obtain the net force by adding the two forces together. If two forces act in opposite direction, we obtain the net force by subtracting the forces from each other.
Since the both linebackers are running East, the net force is obtained as; 105 N + 150 N = 255 N.
