Simple machines {simple machine} use small force exerted over long distance or large force exerted over short distance.
lever
Rods, such as crowbars, can have balance point near one end. Short radius moves short distance and exerts large force, as long radius moves long distance and needs only small force.
inclined plane
Ramps can lift heavy objects short vertical distances, by using small forces over long horizontal distances.
screw
Inclined planes can wind around axis, to allow lifting water short vertical distances using small forces over long horizontal distances.
Wheels on axles {wheel and axle} {axle and wheel} allow objects to move horizontally with no sliding friction. Pulley wheels on axles can hold rope, which can lift weight short vertical distances by pulling rope using small forces over long horizontal distances. Pulleys can alter force direction. One rope can wrap around two pulleys to make a block and tackle, to lift heavy objects short distances with small forces applied over long distances.
Construction levers {crane, machine} {derrick} lift and lower objects using counterbalancing weight.
Forces can redirect using movable connections {joint, connector}|.
Force on ladder steps transmits to both sides and then to ground. Ladders {ladder} have angle to ground. If angle is too large, frictional torque is too small to balance weight torque, and ladder feet slip.
Forces can redirect using connections {strut}| that exert force inward or outward.
Double inclined planes {wedge, machine}|, such as axes and knives, use small force over long distance to exert large force over short distance, to split things or push grooves into softer material.
Actual mechanical-advantage to ideal mechanical-advantage ratio {mechanical advantage}| {efficiency, dynamics} inversely relates to friction. Actual mechanical advantage is lower than ideal mechanical advantage. Actual force Fi exerted on machine divides into force Fo exerted on object-to-move {actual mechanical advantage}: Fo / Fi. Distance moved by output force divides into distance si moved by input force {ideal mechanical advantage}: si / so.
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Date Modified: 2022.0225