Simple Machines Worksheets and Printable Activities

Simple machines increase our ability to do work. The basic types of simple machines include the lever, inclined plane, pulley, screw, Wedge, Wheel and Axle. Below, you will find worksheets that introduce students to simple machines.

What are Simple Machines?

Simple machines are one of the most notable inventions in history that successfully changed the entire engineering field. The tasks that seem simple to us nowadays, like pulling a cart on wheels, were a difficult feat to accomplish around 2000 years ago.

Since there were no wheels in the first place, people had to drag heavy objects around, making their work difficult. The Greek philosopher Archimedes was the first to describe and use simple machines around the 3rd century BC. The 6 simple machines are the wheel and axle, lever, inclined plane, pulley, screw, and wedge. They are all based on a simple principle that work is done when a force acts on an object in the direction of motion.

6 Simple machines are considered the building blocks for more giant, complicated machines. They work on the simple principles of increasing the direction or magnitude of a force or the place where force is applied. These things govern the working of a machine. Simple machines have few or no moving parts, combining to form complex machines. Let us discuss them one by one;

Inclined plane

An inclined plane is simply a sloping surface or a board. It has no moving parts. It has a flat surface raised at an angle from the ground and used to move objects to a higher surface. It is used for moving heavy objects to a raised level. Sliding a heavy object is more manageable than lifting it. The sloping surface gives the advantage of less force compared to the weight of the object being moved.

The amount of effort required to move objects up an inclined plane depends on the level of steepness. A ramp inclined at a steeper level requires more force to move the object. A longer board raised a short distance from the ground will have a lesser slope and will need less force to move objects. An inclined plane was used in ancient Egypt to build pyramids. As the slope decreases, the mechanical advantage increases, but the distance to move the load will be greater.

Lever

A lever consists of a board or a long beam resting on a pivot point, called a fulcrum. The board is free to rotate on the fulcrum.

You can observe the most common example of a lever in a seesaw or wheelbarrow. A lever has 4 parts; the beam, fulcrum, effort, and load. By applying downward force (effort) on one end, the other end (load) is lifted. The fulcrum must be placed close to the load so that less effort is needed to move it. The lever changes your input force's direction and increases its magnitude. Greater distance between the load and point of force applied decreases the effort it takes to lift a heavy object. When the effort and load on a lever are equal to each other, the lever is said to be in equilibrium.

Wedge

A wedge is an object made of wood, stone, metal, or plastic. It is simply a modification of the inclined plane. It has one tapered, thin and sharp end and is used to redirect a large amount of force in a specific sideways direction.

A wedge can be attached to a rod and is used in hammers, axes, etc. It has several purposes; to cut, hold together, tighten or split. Long and thin wedges require less force than short and broader wedges. Decreasing the angle of a wedge lowers the force required to move it a given distance. They are used for cutting logs, and the same principle is used in modern-day vehicles like jets and trains to cut through the air and decrease resistance.

The Wheel and Axle

A circular wheel revolves around a circular rod or shaft, called an axle. Two wheels joined to the two ends of an axle make a simple machine. The wheel and axle work in two ways. Either forced is applied to the wheel to rotate the axle, for example, in a screwdriver. Or an axle is used to rotate the wheels, for example, in a ceiling fan. In both cases, force is transferred from one part to another.

The wheel moves freely over the axle, and the rotational forces have reduced friction compared to a linear force. The wheel and axle are used for moving heavy objects around or moving parts of a bigger machine.

Pulley

Pulley is a wheel having a cord or rope around a groove on its surface. The groove is used to keep the rope in place. One end of the rope is attached to the load, and the other is pulled down to move the load. It works by changing the direction of the force so that it is easier for us to move objects.

This machine is used in elevators and cranes and helps move heavy objects up and down with as little force as possible. The amount of input force required to move the object is half of the actual weight of the object. There are 3 types of pulleys; a Fixed pulley (the axles are fixed in place), a Movable pulley (both the pulley and load can move), and a Compound pulley (which has a combination of pulleys).

Screw

It is an inclined plane wrapped around a shaft. It has a cylindrical shape with a pointed end and a flat, round head. It has grooves or ridges all around the cylinder, and they are known as threads. Screws are used to hold things together, tighten them, and lift heavy items. The effort takes to screw an object depends on the distance between the threads. Less distance means less effort but more turns. Good examples of screws are bottle tops, cork openers, etc. A bolt is also a kind of screw.