L3: SIMPLE AND COMPOUND MACHINES

Simple machine

is a tool or device that reduces the amount of effort needed to do work by changing the direction or amount of force applied.

Lever

a rigid bar used to exert a pressure or sustain a weight by pivoting on its fulcrum.

Fulcrum

is located at the midpoint of the lever arm and the effort is equal to the load, then the lever will be perfectly balanced.

First class lever

the fulcrum is between the efforts and the load (e.g. scissors, seesaw)

Second class lever

the load is between the fulcrum and the effort that provide a mechanical advantage in lifting heavy loads (e.g. wheelbarrow, nutcracker)

Third class lever

the effort is applied between the fulcrum and the load (e.g. broom, baseball bat)

Inclined plane

It is a flat, sloped surface that helps move heavy objects upward by reducing the effort needed. Inclined planes make it easier raised by lifting it straight up or by pushing it diagonally.

Wedge

is a simple machine that has one or two sloping sides used to split, cut, or push objects or materials apart (e.g. knife, nail, axe).

Screw

is a twisted inclined plane wrapped around a cylinder. It converts rotational vtorque into linear motion and compressive force. It is used to fasten objects, raise weights, and transfer force.

Wheel and axle

is one of the fundamental simple machines used to amplify force or speed. It consists of a larger wheel rigidly attached to a smaller axle. This system works on the principle of rotational motion being converted into translational motion or vice versa.

Pulley

consist of a wheel with a groove along its edge for a rope or cable. They are used to redirect or multiply force, allowing heavy loads to be lifted with less effort.

Fixed pulley

changes the direction of force but does not provide a mechanical advantage.

Movable pulley

allows the load to be shared, effectively reducing the effort needed.

Block and tackle pulley

combines multiple fixed and movable pulleys.

Compound machine

are devices that consist of two or more simple machines working together to accomplish a task.