Conservation of Energy

Conservation of Energy In A Nutshell

This video gives you the big picture on how to solve conservation of energy problems. I don't work any actual examples in this one because I want to introduce the concept for you and explain how all these problems are pretty much the same. I also dabble in the Work-Energy Theorem, which some professors make a big deal about and others pretty much ignore.

Conservative vs Nonconservative Forces

In addition to explaining the definition and a few examples of conservative forces and non-conservative forces, in this video I also go through the example of swimming across a swirling pond to give you a more hands-on example of how this actually works.

Kinetic Energy

Think you already know everything there is to know about kinetic energy? Then this video probably isn't for you. This is more of an intro, with a quick problem calculating the speed a baseball would need in order to have the same kinetic energy as a bus (classic question).

Potential Energy (mgh & springs)

This video covers potential energy in general, so you've got your gravitational potential energy and spring potential energy, plus a bunch of other examples that you can put down if your next exam requires a list! (It probably won't.)

Ramp Conservation of Energy Problems

In this video we use conservation of energy to much more easily solve some ramp problems that were a lot more work in the Forces chapters: objects sliding down a ramp with and without friction, a truck smashing up a runaway truck ramp, and a snow boarder getting air in a halfpipe. If problems are easier with energy than with forces and kinematics, why did your teacher wait until now to introduce energy? To make you suffer.

Pendulum & Tarzan Conservation of Energy Problems

In this video we do pendulum problems using conservation of energy, NOT the later physics techniques involving simple harmonic motion (ω, period, etc). Stuff like calculating the speed of a pendulum at the bottom of its arc, or figuring out how high or how fast can swing given an initial height or velocity.

Roller Coaster Conservation of Energy Problems

Based on the teachers around here, roller coasters are a very popular type of test question because you can add so much to it, like centripetal force. The most classic question in this video is to calculate the initial height of a roller coaster so that the cars will make it through a loop-to-loop of radius R.

Work-Energy Theorem Roller Coaster Problem

This problem should maybe have been in the roller coaster video above, but I'm giving it its own video because it is conceptually a bit different from the other roller coaster problems. Most roller coaster problems don't have friction or work, but this one does (brakes slowing down the roller coaster). I also discuss what would have happened if instead the work had accelerated the cars.

Spring Conservation of Energy Problems

Since you'll almost never ONLY be asked to calculate the potential energy of a spring for a given displacement, so the problems in this video incorporate spring potential energy into energy problems involving pendulums and projectiles (if a kid on a pogo stick can be considered a projectile).

Work-Energy Theorem (W=ΔKE+ΔPE)

The Work Energy Theorem is all about conservation of energy. Really it's just another way to write the equation I prefer, which is Ein=Eout. But some teachers really believe in always starting with this thing, so this video covers that and reminds you to be careful of the sign you put on work.