A single conservative force Fx = (6.0x - 12) N (x is in m) acts on a particle moving along the x axis. The potential energy associated with this force is assigned a value of +20 J at x = 0. What is the potential energy at x = 3.0 m?
1) +11 J
2) +29 J
3) +9.0 J
4) -9.0 J
5) +20 J
Answer: 2