Learners discover that energy is not mysterious or invisible in the way we might imagine. Through hands-on demos with rubber bands, balloons, ramps, and pendulums, students see energy in action and learn to distinguish between two forms it takes: kinetic energy, which is actively doing something right now, and potential energy, which is stored and waiting to be released. The lesson builds toward two foundational rules of science: energy must be put in before it can come out, and energy cannot be created from nothing.

Key Ideas

• Kinetic energy is energy that is actively doing something: motion, heat, light, and sound are all kinetic.
• Potential energy is stored energy waiting to be released. A stretched rubber band, a ball at the top of a ramp, and a wound-up spring all have potential energy.
• Energy constantly converts between kinetic and potential forms. In a swinging pendulum, the energy is fully potential at the top of the swing and fully kinetic at the bottom.
• For energy to come out of a system, energy must first go in. Every hands-on demo in this lesson required the student to put energy in first.
• Energy cannot be created. A roller coaster's first hill is always its tallest because the coaster can never gain more energy than it started with.
• Energy and matter are completely separate things. Adding or releasing energy from an object does not change the object's weight.
  
  

Vocabulary

• Kinetic Energy: Energy that is actively doing something right now. Motion, heat, light, and sound are all forms of kinetic energy.
• Potential Energy: Stored energy waiting to be released. Found in a stretched rubber band, a raised weight, a wound spring, or compressed air.
• System: A group of parts working together. Energy moves into, through, and out of systems.

Supplies for Live Class (all helpful, but optional) 

• Ramp (any flat surface on an angle, a book balanced on other books works!)

• Balls or toys to roll or slide down the ramp
• Pendulum (a weight on a string tied to the edge of a table)
• Balloon
• Rubber bands
• Spring-powered toy/wind up toy

Phet Simulation Recommendation: https://phet.colorado.edu/en/simulations/energy-skate-park 

Discussion

• What is the difference between kinetic and potential energy? Can you give an example of each from your everyday life?
• Think about a playground swing. Where does it have the most potential energy? Where does it have the most kinetic energy? What happens in between?
• Can you think of something that starts with potential energy and then changes into kinetic energy?
• Why does a roller coaster need a tall first hill? What would happen if a later hill were taller than the first?
• If energy can't be created, where does the energy come from when you turn on a flashlight, ride a bike, or jump?
• Every demonstration required you to put energy into the system first. What energy did you provide, and what happened to it?
• Can something have both potential and kinetic energy at the same time? Think of a roller coaster, bouncing ball, or swinging pendulum.
• If you stretch a rubber band and then let it go, where did the energy you put into it go?
• What would happen if you could somehow remove all the energy from a moving object? What would happen to its motion?
• Energy and matter are different things. Can you think of an example where you add energy to something without adding more matter to it?
• What do you think would happen if energy actually could be created? How might that change the world?
• Which form of energy do you encounter most often in your daily life: kinetic or potential? Why?

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