Where is energy hiding?
Energy is what makes it possible to do work: lift a load, push something, throw a ball, warm a house. Energy is in people, animals, wind, flowing water and the Sun. Humans get energy from food: after eating we have strength, without food we get tired. People first used the energy of wind, flowing water and their own strength. Energy can be stored: a drawn bow, a squeezed spring, an object on a high shelf and stacked firewood all store energy.
Experiment “Hidden energy”: hook a rubber band over two fingers, stretch it and shoot a small paper ball towards the floor (never at faces!). The stretched band held energy. Also press a spring toy down and release it. Question: where was the energy stored? Safety: never aim the band or ball at anyone; protect your eyes.