A screw is a kind of inclined plane wrapped around  a cylinder. It is a simple machine made out of another simple machine, the inclined plane we learnt about last week.  It is actually an inclined plane that winds around itself.  
Compare a screw to an inclined plane and you will see the  similarities as the thread on a screw goes upward to its head.  A screw has ridges  and is not smooth like a nail.  Some screws are used to lower and raise things. eg  a car jack is used to raise the car so you can change a tyre.  Screws are also helpful to hold things together. Examples are a jar and a lid, a screw, and a light bulb.
No comments:
Post a Comment