Are there only 2 simple machines?

Answer 1

Yes. There actually are only 2 types of simple machines. Even though textbooks or other websites may say there are 6, there are really only 2. Those resources are probably going to say that the types of simple machines are inclined planes, wheel & axle, wedge, screw, lever, and pulleys. The reason why there are only 2 is because simple machines are grouped into twodifferent "families". The lever "family" and the inclined plane "family". The wheel & axle and the pulley both work on the same principles as the lever, while the wedge and screw are inclined planes. Now your probably wondering how that works. Well, if you unraveled a screw (which is not possible, but IF you did) you would get an inclined plane. While a wedge is really just two inclined planes put together. How a pulley is a wheel & axle is pretty hard to understand so read carefully. If you take the top part of a pulley off (because you don't need it) and cut the bottom part off of the pulley (because if you made the rope go in the middle of the whole pulley and were able to cut the bottom off) you would get something that looked like an wheel & axle. It really is a wheel & axle! So really all of those seemingly different types of simple machines are just 2 simple machines.