Wheelbarrow (thing)

A wheelbarrow is a class 2 lever designed primarily for small-scale outdoor transport of such things as dirt. It is actually, however, used by clever people to carry just about anything, including refrigerators, boats, other people, even radioactive waste if you believe everything you see in The Simpsons (check out episode 8F13). Wheelbarrows are even sports equipment. (Freestyle wheelbarrow is considered an extreme sport, thanks to Aeroplane for pointing that out.) (/msg me if you have used a wheelbarrow in some other unorthodox way and I might add it to the list!)

The first wheelbarrow: The wheelbarrow is considered by some to be invented by the Chinese general Chuko Liang, who lived from 181-234 A.D., although descriptions of wheelbarrows in China predate this by several hundred years. Liang's wheelbarrow had 2 wheels and required 2 people to operate. It was used to transport supplies to soldiers. (see inventors.about.com/library/inventors/blwheelbarrow.htm)

Here is the basic idea of what a wheelbarrow looks like.
               _______________
               \             /
                \    Load   /
         ________\_________/__
        (_____________________)   
          /\             /^\
         Force          | . |
                         \_/

The wheelbarrow utilizes two simple machines in its operation: The lever and the wheel. The lever, a class 2 lever, allows a load to be lifted with relative ease, with the wheel acting as the pivot. The wheel more importantly eliminates sliding friction when transporting the load from one location to another.

Tips for using the wheelbarrow:

1. If the load is heavy, try to load onto primarily the front end of the wheelbarrow so that the center of mass is close to the pivot. This reduces the force necessary to lift the load. Don't get carried away, though, or you might end up with a class one lever, which is in my experience extremely annoying to use as a wheelbarrow.
2. Check that the wheel is not flat! It's not fun to load a wheelbarrow with 500 lbs of bricks and then discover the wheel is flat.
3. If your wheelbarrow gets stuck in a little hole in the yard, or you need to get it over a small step or bump, simply turn it around and pull it backwards. When you push a wheelbarrow, the weight of the load is actually driving the wheel into the ground, so the effect of any small bump is amplified. So make like an ox, and pull the wheelbarrow instead.