Kinetic energy

[mirandamirandaParticipant]

I always understood kinetic energy to be movement energy. But in this lesson you describe it as being all forms of ‘active’, non-potential energy including heat, light and electric energy. I am struggling with using the term ‘kinetic’ to describe these forms of energy! Would you mind clarifying?

[Bernard NebelKeymaster]

Thank you for your question, Mirandamiranda. Think of kinetic energy as the energy moving through space. Heat does not stay put; it is constantly moving from a warmer place toward a cooler place. Nor does light; light is photons (electromagnetic waves) traveling at the speed of light. As soon as you turn off the source, its light travels on and the room becomes dark. Electricity is electrons traveling, usually through a wire. You may have a charged object, static electricity (potential energy) but an electric current or discharge is electrons in motion traveling from one place to another. With classic movement energy, the ball, for example, is the same whether it is moving or not. Therefore, think of the energy as something different than the ball. The energy is being carried from one place to another by the ball’s moving.

I hope this helps, but please ask further.

Bernie Nebel

[mirandamirandaParticipant]

This does make sense, thank you. I found it confusing because other explanations (eg Wikipedia) describe kinetic energy as opposed to potential energy, but the examples used tend to be only movement energy. I was also taught this simplified definition – always hard to let go of those things! Thank you for clarifying.

[Bernard NebelKeymaster]

Thanks miranda. I would just like to add another way to think of heat, light, and electricity as being forms of “active” (kinetic) energy. Heat actively cooks the beans; electricity actively makes the TV work; light actively interacts with the cells of the eye and enables us to see; the moving ball smashes through the window. Kids will have fun thinking of other such examples that reinforce the idea that heat, light, electricity, and movement are active forms of energy, that is forms of energy that directly cause action.

Bernie Nebel

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