Headline Clickable. Whether raw or cooked, food can be chock-full of dangerous bacteria long before you can smell it. Perishable food (like chicken and other meats) should be tossed if left out at room temperature more than two hours (much less if in a warm room).
Catapult physics is basically the use of stored energy to hurl a projectile (the payload), without the use of an explosive. The three primary energy storage mechanisms are tension, torsion, and gravity.
Key Concepts. Catapults store energy until you hit the trigger. You store energy in a rubber band every time you stretch it out - the pull you feel from the rubber band is called potential energy. Catapults store potential energy by stretching ropes and rubber bands, and even by bending and flexing the wooden lever.