Planes and Levers

Two simple machines that help people move things, or even themselves, is the inclined plane and lever. They can be seen everywhere in society, on streets, businesses, and in homes. They help make things easier to move from one place to another place, or to use for everyday actions.

The inclined plane has a sloping surface, tilted at different angles, and is considered a machine that can help move objects more easily. It is commonly called a ramp. People use them to move from one floor level to another, or use it to carry a heavy load up a ramp instead of using stairs.

Moving things up one or more stairs is much more difficult because of the distance involved and the force of gravity. However, using an inclined plane shortens the distance and the load is lighter, but it will take a bit longer to move the object. There is basically an exchange or trade of force for the longer distance. Overall, it will take less effort but may take more time, plus heavier loads could be moved that may not have been possible otherwise.

There are several examples of inclined planes, including use by people in wheelchairs who use them to avoid steps by going up a ramp; stroller use on sidewalks, or even a slide at a playground. Kids can move from one level to the next much more easily on a slide than using a ladder or steps.

The second machine which is helpful is the lever. A lever is a bar that uses a single point to support something. The single point is called the fulcrum. One can think of a see saw, with the center of the long board located at the fulcrum. There are three parts of a lever: The effort, fulcrum, and load.

The effort is the force applied to use the lever. The fulcrum, as mentioned earlier, is the supporting point, and the load is the force applied on the lever.

There are also three classes of the lever and each is used to help the it be used more efficiently. In the first class lever, the fulcrum is between the load arm and effort arm, with an equal distance in between. Picture a see saw with the effort on one end and the load on the other end. The effort and load move in the opposite direction just like two kids on a see saw move it up and down.

For the second class lever, the fulcrum is at one end, the load is in the middle, and the effort is at the opposite end. In this class, the effort and the load move in the same direction. Think of a wheelbarrow. The load is the dirt, the fulcrum is the front wheel, and the effort is the handles. The wheelbarrow is much easier to move as the effort is less strenuous for the user of the wheelbarrow.

The third class lever is special from the other two. The effort and load is the opposite of the second class lever, with the fulcrum still remaining on the other end. Think of a person's forearm and a nail being hammered into wood. The fulcrum is the elbow, the bicep muscles is the effort, and the load is the resistance of the wood.

In summary, there are inclined planes and levers used every day in many places allowing work to be done much more easily. An example of an inclined plane is a ramp or slide. Levers are divided into three different classes, first, second, and third. First class levers include a see saw, scissors, and pliers. Second class levers include wheelbarrows, doors, and staplers, and third class levers include forearms, brooms, and a baseball bats.