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Energy

Energy drives the world around us. Everything from a fish swimming to an apple falling from a tree needs energy in order to work. Think about a roller coaster and the electricity causing the motor to run, which then pushes the car to the top of the first hill. Then motors shut off, the car rolls down the hill and picks up speed, and then the roller coaster uses that speed to go over smaller hills, through loop-de-loops, and into corkscrews.

One of the principles of physics that governs how we work in science is called the Law of the Conservation of Energy. This says that energy can not be created nor destroyed, only changed. Take a car, for instance. Energy is stored in the gas that the car hasn't used yet, and is transformed to power the car. As the roller coaster goes over the first hill, its energy is converted, not destroyed.

Roller coasters are an example of what is called Mechanical energy transfer. Mechanical energy is related to how things move, and is broken up into two main types:

Potential Energy is stored energy that can be used to create motion. i.e. something up high has potential energy from gravity that will cause it to fall.

Kinetic energy is the energy of the motion of an object. i.e. when you are running, you have kinetic energy.

Ask the class: When a roller coaster is at the top of the highest hill, what type of energy does it have? (It has potential energy).
What type of energy does it have when it is at the bottom of the hill? (It has kinetic energy).

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