Machines, Simple (Encyclopedia of Science)
A simple machine is a device for doing work that has only one part. Simple machines redirect or change the size of forces, allowing people to do work with less muscle effort and greater speed, thus making their work easier. There are six kinds of simple machines: the lever, the pulley, the wheel and axle, the inclined plane, the wedge, and the screw.
We all do work in our daily lives and we all use simple machines every day. Work as defined by science is force acting upon an object in order to move it across a distance. So scientifically, whenever we push, pull, or cause something to move by using a force, we are performing work. A machine is basically a tool used to make this work easier, and a simple machine is among the simplest tools we can use. Therefore, from a scientific standpoint, we are doing work when we open a can of paint with a screwdriver, use a spade to pull out weeds, slide boxes down a ramp, or go up and down on a see-saw. In each of these examples we are using a simple machine that allows us to achieve our goal with less muscle effort or in a shorter amount of time.
Earliest simple machines
This idea of doing something in a better or easier way or of using less of our own muscle power has always been a goal of humans. Probably from the beginning of human history, anyone who ever...
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Simple Machines (Science Experiments)
Wheel and Axle: How can changing the size of the wheel affect the amount of work it takes to lift a load?
Design Your Own Experiment
When most people envision machines, the image probably does not include a simple screwdriver or pencil sharpener. Yet these devices are also machines. A is any object that makes work easier by altering the way in which the work is accomplished. Put another way, a machine can use a smaller force to overcome a larger force. In physics, workForce applied over a distance. is defined as force applied over a distance. For example, a person does work when pushing a shopping cart down an aisle, yet does no work when pushing against a closed door.
Simple machines have few moving parts, or sometimes none at all. They are the building blocks for machines of all levels of complexity and all mechanical devices. People have been using simple machines for thousands of years. Zippers, staplers, nails, and scissors are just a few examples of common modern-day machines.
Machines can enlarge and change the direction of a force, yet all machines must follow the...
(The entire section is 3790 words.)