Exploratorium+Project

Exploratorium Project

Topic: Mechanical Energy Chris Hallowell, Mike Solimano, Jake Aronson

Script: Does anyone have an idea of what energy is? As humans, we do a lot of things to gain energy, but in physics, energy takes on a whole new meaning. So who here likes rollercoasters? Well in order to explain the first part of mechanical energy, I am going to use this picture of a rollercoaster to help everyone. As the roller coaster makes its way up to the top of the hill, it is constantly gaining energy as it rises. This energy that it is gaining is called gravitational potential energy. Yes I know, it sounds like a scary few words but let me help you to understand it a bit better. Does everyone know what gravity is? How about the word potential? As the rollercoaster makes its way up the hill, it is gradually going higher and higher. This means that when it is at its highest point the force of gravity has a lot of potential to have an effect on the cars. The higher something is in the air, the more “GPE” it has. This leads us right into the next part of the rollercoaster ride, when the cars go fast. As soon as the cars start to go down the hill, the energy that was gained in GPE is then turned into kinetic energy. Kinetic means anything that has to do with motion. The faster the cars go, the more KE they have. After a nice, long ride on the coaster, eventually it has to come to a stop and slow down. How do rollercoasters slow down? Brakes exactly, and what those brakes are doing is what we call doing work on the rollercoaster. Work is the exertion of a force over a certain distance, or in this case the force of the brakes on the track stopping the cars. So after you get off a roller coaster the next time safely, make sure you say thank you to work for slowing your cars down properly. The last part of mechanical energy that unfortunately can’t really be seen on a roller coaster is elastic potential energy. This energy is often created in rubber bands or springs. Anything that can stretch or pull can create EPE.

Demo 1: Heavy Ball Pendulum... GPE, KE Materials: Heavy Ball with Hook, Strong String, Low enough ceiling to put a hook

Demo 2: Dart Gun (with plane) EPE, W (done by me) /// Spring Pipe Shot Materials: Ms. Burns's dart gun, Pipe Device to shoot the wood pieces

Demo 3: Ramp with Ball ... GPE, KE, W (friction) Materials: Curved ramp in physics room, metal ball (small and large), White ball

Demo 4/Activity: Sky Streak Rubber Band Powered Airplane W, EPE, GPE, KE Materials: Airplane Kit