A roller coaster is a perfect example of energy conversion and mechanics and can substitute big carriages for marbles. Using gray foam tubing, which usually comes in 6 ft lengths to insulate water pipes, split the tubes in half lengthwise and begin by taping one end of the tubing up high (to a desk, wall, table or chair for support) to create twists, turns and loops. Cardboard tubes work well for coaster tunnels.
By using marbles, measure the velocity of the marble at different points along the track to calculate the kinetic energy. Find an average of 10 tests.
In real life, the string of cars is pulled up to the crest of the tallest point on the roller coaster. One by one, the cars start downhill on the other side, until gravity takes over and the full weight of the train is careening down into curves, twists, and turns. The roller coaster is a great example of conversions between potential energy (stored energy) and kinetic energy (the energy of motion). As the cars are being pulled up to the top of the first hill, they are acquiring potential energy. The chain that pulls them up the hill works against the force of gravity. At the top of the hill, the cars' potential energy is at its maximum.
When the cars start down the other side, this potential energy is converted to kinetic energy. The cars pick up speed as they go downhill. As the cars go through the next uphill section, they slow down. Some of the kinetic energy is now being converted to potential energy, which will be released when the cars go down the other side. The first hill on the roller coaster should be the highest, because not all of the potential energy is converted to kinetic energy. Some of the potential energy is lost in other energy conversion processes, through friction-causing heat and sound. The cars also cause the supporting structure to flex, bend, and vibrate. This is motion, so it is kinetic energy, but of the track, not the cars.
By using marbles, measure the velocity of the marble at different points along the track to calculate the kinetic energy. Find an average of 10 tests.
In real life, the string of cars is pulled up to the crest of the tallest point on the roller coaster. One by one, the cars start downhill on the other side, until gravity takes over and the full weight of the train is careening down into curves, twists, and turns. The roller coaster is a great example of conversions between potential energy (stored energy) and kinetic energy (the energy of motion). As the cars are being pulled up to the top of the first hill, they are acquiring potential energy. The chain that pulls them up the hill works against the force of gravity. At the top of the hill, the cars' potential energy is at its maximum.
When the cars start down the other side, this potential energy is converted to kinetic energy. The cars pick up speed as they go downhill. As the cars go through the next uphill section, they slow down. Some of the kinetic energy is now being converted to potential energy, which will be released when the cars go down the other side. The first hill on the roller coaster should be the highest, because not all of the potential energy is converted to kinetic energy. Some of the potential energy is lost in other energy conversion processes, through friction-causing heat and sound. The cars also cause the supporting structure to flex, bend, and vibrate. This is motion, so it is kinetic energy, but of the track, not the cars.
