Wikijunior:How Things Work/Wedge
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A wedge is something that is thicker on one end or edge and thinner on the other end or edge, like the shape of a slice of pie. Wedges are one of the six simple machines.
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[edit] Who invented it?
The origin of the wedge is unknown, because it has been in use from as early as the stone age. The wedge is one of the oldest machines; when someone made an arrowhead, they were making a wedge.
It's not wrong to assume that wedge is really one of the very first inventions of humans. Other first inventions are the hammer, spear (a long stick with a sharpened point) and lever. Our first example of a working wedge is the knife, which humans made before they could master fire or any other thing. The first knife was made by selecting a broken piece of a stone that could fit easily in your hand and was sharp enough to cut meat, grass and bark. The oldest knives made from stone date back millions of years.
Of all the animals only some apes use sticks for hunting or big stones in the way we use a hammer to smash nut fruits which might otherwise be impossible for them to eat. But none of the animals use knives or wedges.
[edit] How does it get power?
Its power is derived from outside forces acting on it.
[edit] How does it work?
[edit] How dangerous is it?
Because a wedge is thin on one edge or end, that means the thin part is sharp. There are many wedges you have to be careful with, like knives and scissors.
[edit] How does it vary?
Common examples include knives, axes, nails, staplers and doorstops.
[edit] How has it changed the world?
Without wedges, we would not have been able to cut wood or hunt animals.
[edit] What idea(s) and/or inventions had to be developed before it could be created?
The only thing that people had to know was how to chip rock to make it sharp. Now we usually use metal for most wedges.
