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.
Another type of siege weapon was the trebuchet, which is a form of catapult, but the power source was different. The trebuchet used gravity and weights to hurl the projectile. The catapult used in the Middle Ages was powered by one of four different sources. These were tension, torsion, traction, and gravity. Let's take a closer look at each power source and how it worked.