CALC Electric charge is distributed uniformly along a thin rod of length a, with total charge Q. Take the potential to be zero at infinity. Find the potential at the following points (Fig. P23.73): (a) point P, a distance x to the right of the rod, and (b) point R, a distance y above the right-hand end of the rod. (c) In parts (a) and (b), what does your result reduce to as x or y becomes much larger than a?

Potential Energy and Conservation of Energy Conservative and Nonconservative Forces ● Conservative force: The work it does is stored in the form of potential energy that can be used at another time. ○ Gravity is a conservative force ○ Friction is a nonconservative force ● Conservative forces are path independent ● Work done by a nonconservative force is path dependent ● If we pick up a block and put it on a shelf, we have done work on the block. We can get that energy back if the block falls off the shelf; in the meantime, we say the energy is stored as potential energy. ● Springs ○ Conservation of Mechanical Energy ● The initial energy of the system is the same as t