SIMPLE MACHINES VIDEO

SIMPLE MACHINES

Simple machines make work easier for us by allowing us to push or pull over increased distances. 

There are SIX simple machines: 

Type	Example	Activity
1.   Pulley - How Stuff Works A pulley is a simple machine that uses grooved wheels and a rope to raise, lower or move a load.		Pulleys
2.   Lever - Enchanted Learning animations A lever is a stiff bar that rests on a support called a fulcrum which lifts or moves loads.		Levers
3.   Wedge - pictures using LEGO bricks A wedge is an object with at least one slanting side ending in a sharp edge, which cuts material apart.		Wedges
4.   Wheel & Axle - Activity using pencils and thread spools A wheel with a rod, called an axle, through its center lifts or moves loads.		Wheels
5.   Inclined Plane - pictures using LEGO bricks An inclined plane is a slanting surface connecting a lower level to a higher level.		Inclined Planes
6.   Screw - Activity using pencil and paper in a new way A screw is an inclined plane wrapped around a pole which holds things together or lifts materials.		Screws

LEVERS

Levers are one of the basic tools that were probably used in prehistoric times. Levers were first described about 260 BC by the ancient Greek mathematician Archimedes (287-212 BC).
A lever is a simple machine that makes work easier for use; it involves moving a load around a pivot using a force. Many of our basic tools use levers, including scissors (2 class 1 levers), pliers (2 class 1 levers), hammer claws (a single class 2 lever), nut crackers (2 class 2 levers), and tongs (2 class 3 levers).

A Type 1 Lever.

A Type 2 Lever.

A Type 3 Lever.

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A Type 1 Lever.

In a Type 1 Lever, the pivot (fulcrum) is between the effort and the load. In an off-center type one lever (like a pliers), the load is larger than the effort, but is moved through a smaller distance. Examples of common tools (and other items) that use a type 1 lever include:

Item		Number of Class 1 Levers Used
see-saw		a single class 1 lever
hammer's claws		a single class 1 lever
scissors		2 class 1 levers
pliers		2 class 1 levers

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A Type 2 Lever.

In a Type 2 Lever, the load is between the pivot (fulcrum) and the effort. Examples of common tools that use a type 2 lever include:

Item		Number of Class 2 Levers Used
stapler		a single class 2 lever
bottle opener		a single class 2 lever
wheelbarrow		a single class 2 lever
nail clippers		Two class 2 levers
nut cracker		Two class 2 levers

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A Type 3 Lever.

In a Type 3 Lever, the effort is between the pivot (fulcrum) and the load. Examples of common tools that use a type 3 lever include:

Item		Number of Class 3 Levers Used
fishing rod		a single class 3 lever
tweezers		Two class 3 levers
tongs		Two class 3 levers

The world is filled with motion. Some motions just happen: the Earth revolves around the Sun, snowflakes fall to the ground, waves surge across the sea. Other motions are under our control. We walk. We pick up things. We ride our bikes. But whether the movement is a planet revolving or you playing a game, the motion happens because of force.

Just what is Force? Force is just a fancy word for pushing or pulling. If I push on something or pull on it, then I am applying a force to it. Forces make things move or, more accurately, make things change their motion. Two natural forces that affect most of the motion we are aware of are the force of gravity and electromagnetic forces. Gravity produces a force that pulls objects towards each other, like a person towards the ground. And magnetism produces a force that can either pull two magnets together or push them apart, depending on how they’re lined up. What is Friction? Friction is a force that makes the objects move together or at least have more nearly the same velocity. Say you were pushing a toy train across the floor. It doesn't take much effort or force, because the toy is light. Now say you try to push a real train. You probably can't do it because the force of friction between the train and the ground. The heavier the object, the stronger the force of friction. What is Gravity? Gravity produces a force that pulls objects toward one another. It is the force that keeps the Earth revolving around the sun and it's what pulls you to the ground when you trip. Newton’s laws of Motion Some consider Sir Isaac Newton to be the greatest English mathematician of his time and perhaps one of the greatest scientists the world has known. According to a story, Newton saw an apple fall to the ground and he figured out that the same force which caused the apple to fall also governed the motion of the Moon and the planets. In 1687 Newton published his three laws of motion in the "Principia Mathematical Philosophies Naturalism”. His three laws explained how the concepts of force and motion work.