Simple and complex machines are used in our daily lives and in agriculture. Machines are devices that help make work easier. A simple machine is a device that changes the magnitude or direction of a force—a lift, a push, a pull, or anything that makes an object move or remain still. A complex machine consists of two or more simple machines working together. Most machines consist of multiple elements that work together in a complex way. But no matter how complex they are, machines are made up of one or more simple machines. There are six types of simple machines—wedge, inclined plane, screw, lever, wheel and axle, and pulley.
Wedge: A wedge is a triangle-shaped object with one pointed end and one thicker end. It is used for raising, holding, or splitting objects. A wedge makes it easier to split things apart. When the wedge is pushed down, the object it is pushed into splits apart. For example, after a farmer harvests apples and sells them, the apples are often peeled, cored, and sliced to be used into pies. The knife, apple peeler, and cutter used to prepare the apples are wedges.
Inclined Plane: An inclined plane is a flat surface that is higher on one end. It is used to move objects to a lower or higher place. It is much easier to move a heavy weight up or down if an inclined plane is used. A ramp (a type of inclined plane) is very useful when a cattle rancher loads cattle onto trucks to move them from one pasture to another.
Screw: A screw is a rolled up inclined plane. It is used to hold objects together or lower and raise things. In an agricultural machine called a combine, an auger—or moving screw—pushes grain into a container.
Lever: A lever is a device which pivots on a fixed point called a fulcrum. A lever makes it easier to move heavy things. Levers concentrate a force around a pivot point. A cattle rancher needs to use fences around the pasture. The heavy gates open and close easier because they have hinges that are levers. The gate fasteners are often levers too.
Wheel and Axle: A wheel is a disk or circular object arranged to revolve on or along with an axle that passes through its center. An axle is the bar on which or with which a wheel or wheels turn. Wheels allow things to roll instead of slide when a force is applied. Wheels help move objects.
Pulley: A pulley is a wheel over which a rope or chain passes. It is used to life or move things. Pulleys make lifting easier for people by changing the direction of a pull. There are many different kinds of pulleys that lift and move heavy loads. A pulley can be used to place hay in a barn.