Levers, Pulleys and Gears
Levers, pulleys, and gears are simple mechanisms that help us apply a smaller force to achieve a greater effect, making tasks easier. These mechanisms use mechanical advantage to multiply the force applied, allowing us to lift heavy objects, move loads with less effort and transfer motion efficiently.
A lever consists of a rigid bar that pivots around a fixed point called a fulcrum. By placing the fulcrum closer to the load and applying force at the opposite end, a small effort can lift a much heavier object. This is why crowbars, seesaws and bottle openers make lifting and prying easier.
A pulley is a wheel with a rope or chain running over it, used to lift loads. A simple pulley changes the direction of force, while a system of multiple pulleys, called a block and tackle, reduces the effort needed to lift heavy objects. Pulleys are used in cranes to lift heavy materials on a building site, to allow elevators to rise and fall, and to lift and drop the sails on sailing ships.
Gears are toothed wheels that transfer force and motion. When gears of different sizes interlock, they can increase speed, change direction, or amplify force. For example, in bicycles, small gears require less force to turn larger gears, making pedaling easier while maintaining speed. Gears are also used in clocks, cars and industrial machines, helping to control and distribute mechanical power efficiently.