Riding the Energy Train

Our discussion of work and energy continued today with various people starting at various places. B Block and F Blocks took on the topic of potential energy, with the two examples on stage now being gravitational potential and elastic potential. Easily accessed for work, unlike chemical or nuclear, those forms of potential energy get lumped, along with kinetic energy, as mechanical energy. We looked at both of those energies conceptually and mathematically and will review our work tomorrow before moving on to conservation of energy.

Which was where C Block picked up today. Energy does not care what it is at any time - it readily converts and transforms between forms and types. The only caveat is that the total value is always conserved. Mechanical energy, no so much, due to transformations into unusable, non-mechanical forms, but total energy most certainly is conserved quantity. For mechanical energy, as long as friction and other factors are kept at bay, mechanical energy is conserved well enough to make some good predictions about the behavior of objects. Common problems involve solving for a final velocity for an object falling from a height (with or without an initial velocity)and predicting how high something will rise given a launch velocity. Sometimes the problems would be accessible using kinematics formulas, but they fall down when acceleration is not constant and get complicated when the motion covers two or three dimensions getting to its final location. We'll go over your homework problems tomorrow before moving into power.

E Block began their discussion of work and the work-kinetic energy theorem after a discussion of yesterday's lab. Although we highlight the relationship between work and kinetic energy, a similar relationship exists between work and change of potential energy. We'll dig deeper into potential energy tomorrow, highlighting the one you've worked with in lab, gravitational potential energy and adding a new one, elastic potential energy.