Machines
Thousands of years
ago, a caveman named "Ug Lee," needed a better way to cut up his Woolly
Mammoth that he stoned to death. He took his favorite rock, and tried
his best to remove some choice morsels. However he realized that his
trusty rock just wasn't completing the job. His wife "Hoam" told Ug that
he should try her favorite stick. Ug realized that if he attached his
favorite rock to Hoam's favorite stick, his job might be a little
simpler. Thus, Ug and Home Lee invented the first simple machine.
Throughout the centuries, humans have been challenged to make life
easier. One way to accomplish this was to invent tools to make jobs less
difficult. We know these tools as machines. The tools most people think
about when they hear the word "machine" are actually a combination of
two or more simple machines. There are six types of simple
machines: the inclined plane, wedge, screw, levers, pulley, and the
wheel and axle.
Compound machines are two or more simple machines working
together. A wheelbarrow is an example of a complex machine that uses a
lever and a wheel and axle. Machines of all types make work easier by
changing the size or direction of an applied force. The amount of effort
saved when using simple or complex machines is called mechanical
advantage or MA.
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