Expert: Jeanette A - 11/24/2008

Question
Dear Ms. Jeanette,
 On a free fall ride when is there more kinetic energy and when is there more potential energy?

                            Thanks,
                               Collin

Answer
Hello Collin,

Potential energy is the same as stored energy. The "stored" energy is held within the gravitational field. When you lift a heavy object you exert energy, which later will become kinetic energy when the object is dropped. A lift motor from a roller coaster exerts potential energy when lifting the train to the top of the hill. The higher the train is lifted by the motor the more potential energy is produced, forming a greater amount of kinetic energy when the train is dropped. At the top of the hill the train has a huge amount of potential energy, but it has very little kinetic energy.

The word "kinetic" is derived from the Greek word meaning to move, and the word "energy" is the ability to move. Therefore, "kinetic energy" is the energy of motion - it's ability to do work. The faster the body moves the more kinetic energy will be produced. The greater the mass and speed of an object the more kinetic energy there will be. As the train accelerates down the hill the potential energy is converted into kinetic energy. There is very little potential energy at the bottom of the hill, but there is a great amount of kinetic energy.

Hope that explains your question.

Kind Regards,
Jeanette