일반물리학 1 — Potential Energy and Conservation of Energy: Problem 26

26 A conservative force $\vec{F} = (6.0x - 12)\hat{i}$ 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 27 J at $x = 0$. (a) Write an expression for $U$ as a function of $x$, with $U$ in joules and $x$ in meters. (b) What is the maximum positive potential energy? At what (c) negative value and (d) positive value of $x$ is the potential energy equal to zero?