Conservation of Mechanical Energy

Conservation of momentum is generally simple and straightforward - after all, there is only one kind of (linear) momentum (mv), and if no external forces act on a system, it is conserved. Momentum after equals momentum before - easy! Conservation of energy, on the other hand can get very complicated - there are many forms of energy, and accounting for all of them can be very taxing.

We are going to keep things as simple as possible by restricting our attention to mechanical energy - and in particular, we will consider only three types of energy:

kinetic energy (KE) of large, human-scale objects (as opposed to the kinetic energies of and within the atoms that make up the objects),
gravitational potential energy (GPE) - energy stored by the gravitational force, and
elastic potential energy (EPE) - energy stored by springs. (NOTE: Physics 1 students will not need to be able to perform calculations with EPE, but should understand the concepts involved.)

last update November 21, 2007 by JL Stanbrough