PS 8 Articles

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All 3 types of levers - first-class, second-class, and third-class - are found in the human body. The forces exerted by muscles in your body can be increased by first class and second class levers, while third class levers increase the range of movement of a body part. Examples of how the body uses levers to help it move are shown here. 

First class levers - The fulcrum lies between the input force and the output force. Your head acts like a first class lever. Your neck muscles provide the input force to support the weight of your head. 

Second class levers - The output force is between the fulcrum and the input force. Your foot becomes a second class lever when you stand on your toes. 

Third Class lever - The input force is between the fulcrum and the output force.  A third class lever increases the range of motion of the output force. When you curl with a dumbbell your forearm is a third class lever. 

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Imagine an army of tiny robots each no bigger than a bacterium swimming through your bloodstream. Welcome to the world of nanotechnology - the science of creating molecular sized machines. These machines are called nanobots. 

The smallest of these machines are only billionths of a meter in size. They are so tiny that they can do work on the molecular scale. 

Nanotechnologists are predicting that within a few decades they will be creating nanobots that can do just about anything, as long as its small. Already, nanotechnologists have built gears 10,000 times thinner than a human hair. They’ve also built tiny molecular “motors” only 50 atoms long. At Cornell University, nanotechnologists created the world’s smallest guitar. Its approximately the size of a while blood cell and even has 6 strings. 

In the future, they might transmit your internal vital signs to a nanocomputer, which might be implanted under your skin. There the data could be analyzed for signs of disease. Other nanomachines then could be sent to scrub your arteries clean of dangerous blockages, or mop up cancer cells, or even vaporize blood clots with tiny lasers. These are just some of the possibilities in the imaginations of those who are studying the science of nanotechnology.