A single conservative force F = (7.0x - 10)i N, where x is in meters, acts on a particle moving along an x axis. The potential energy U associated with this force is assigned a value of 28 J at x = 0. (a) What is the maximum positive potential energy? At what (b) negative value and (c) positive value of x is the potential energy equal to zero? (a) Number i Units (b) Number i Units (c) Number Units V