Chapter 3 of Johann’s Physics book covers the basic concepts of potential and kinetic energy. The teacher’s manual gives examples to get kids thinking about kinetic energy (the energy of motion) in a way they can relate to: a fast moving car, a basketball sitting still on the floor, a fast moving toddler versus a very tired, slow moving parent.
The formula for kinetic energy is:
KE = 1/2 mv2
where m is the mass of the object and v is the velocity or speed of the object. This means that heavier objects will have more kinetic energy than lighter objects at the same speed. Slower objects will have less kinetic energy than faster ones with the same mass. But the formula also explains scientifically what I and all parents who had a young child have experienced:
KE (Johann at age 3) = 1/2(16kg)(3 meters/second)2 = 72 Joules
KE (Me) = 1/2 (59kg)(1 meter/second)2 = 29.5 Joules
Clearly Johann had much more kinetic energy than I ever did!
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