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.
A catapult is a type of machine used as a weapon to throw rocks or other things such as hot tar, that would cause damage to something else. Often, catapults were set on higher ground or on castle towers to let them shoot farther. They shot rocks to break castle walls, or pitch or hot tar to set the target on fire. Catapults use weights and levers to send the rocks or other things into the air. They do not throw as far as modern weapons do, and are not useful in modern warfare. Catapults were common in the past, especially the Middle Ages. Nowadays catapults are used to study old weapons, and as experiments (for example in physics or engineering classes).