Simple machine timeline
1. The wheel (circa 3500 BCE) - The wheel was one of the first and most important simple machines. It allowed for easier transportation of goods and materials.
2. Levers (circa 300 BCE) - Levers were discovered by the ancient Greeks and were used to lift heavy objects. Archimedes famously said, "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."
3. Pulleys (circa 150 BCE) - Pulleys were also discovered by the ancient Greeks and are used to lift heavy loads. They work by decreasing the amount of force needed to lift an object.
4. Inclined plane (circa 260 BCE) - The inclined plane is a flat surface tilted at an angle. It can be used to move objects up a height with less force than lifting them straight up. Examples of inclined planes include ramps and stairs.
5. Screw (circa 200 BCE) - The screw is a spiral inclined plane and is used to hold things together or to lift things up. It works by rotating the screw, which moves it up or down.
6. Wedge (circa 4000 BCE) - The wedge is a triangular shaped tool used for splitting objects apart. Examples of wedges include axes, knives, and chisels.
7. Gear (circa 300 BCE) - Gears are rotating machines that transfer motion and energy from one part to another. They are used in many machines today, from clocks to cars and are often used to increase torque or force.