A few weeks ago I bought a pair of Magnum combat boots for various reasons (working, airsoft, hiking, etc). They are surprisingly light and comfortable. The tag on the shoe mentions that it is “slip resistant.” This means that, as a whole shoe, the boots have a very high coefficient of static friction. Because the force of static friction is directly related with normal force and the coefficient of static friction, a higher coefficient of static friction means that it takes more force to over come the force of friction and "slip". To test this, I went walking around in my bathtub with the boots on, and it was awesome. It was very hard for me to “slip” (where the force of the forward motion of my foot exceeds the force of friction provided by my boots) even in a puddle on the smooth surface of the bathtub. This made me wonder, however, why causes such high coefficient of friction. I initially thought it was the material, the rubber soles, but I also have rubber slippers, and they slip (no pun intended) very easily under the same conditions. This drove me to research a little further on the internet about friction. The answer was water dispersion. The soles of my boots are designed in such a way to disperse water over a larger area. Water acts as a lubricant, which reduces the coefficient of friction. Because my slippers are rather worn out and are almost completely smooth at the bottom, they don’t disperse water very well, and therefore get the full lubricating effect of water.
These suck at water dispersion =(
The boots, however, have many grooves in which water can go into so there is less water lubricating the parts of the sole that come in contact with the ground (or whatever surface I’m walking on).
These are awesome at water dispersion =)
Walking in a bathtub with boots on can be a fun an educational activity!
