When you rub any two things together, this is called friction. It can be wiping a cloth across a table to wipe it clean or your boots as they skid along ice or snow. It can even be the air going by the car as you drive down a street; or can involve liquids when a boat skirts over water. Friction can also be something that is rubbing in an impact, such as a hammer that strikes a nail.
Scientists are slightly baffled at the real cause of friction. It is assumed that it is caused due to the rough edges of one object touching the rough edges of another. The actual ‘edges’ could probably only be seen in a microscope or some other highly technological tool, but it is believed that the process actually breaks off part of the rough edges of one or both objects.
- When you rub two things that are soft together, even when they are squishy soft, friction occurs. In this case, it is believed that the molecules are actually being attracted together.
- When two objects are pushed together harder there is more friction created. An example of this is when you really push both of your hands together, you find that it is difficult to rub them up and down or even move them in any direction. The same thing when you push hard on your bike brakes, it slows everything down quicker and you will come to a quick stop.
Objects that have more mass allows gravity to pull harder on them. An example of this might be an iron cube versus a wooden cube. An iron cube has more mass than a wooden cube and is more difficult to move when you put friction on it than the cube of wood.
Sold objects usually have more friction than liquid objects when they are pushed together. Two solid objects might be your feet walking across the dry floor, however if you walk across a wet floor, your feet are solid and you can slip on the liquid.
One of the things that happens when two objects rub against each other is that they both slow down. There is a scientific formula that states it: energy = mass x velocity. An explanation of this would be that if the objects lose velocity without gaining any mass, they have to have a release of energy to keep everything balanced or equal.
One of the methods of the release of energy due to friction is through the generation of heat. The objects lose electrons in the process of friction. You can actually make this happen by rubbing your hands together quickly. You see that they get warmer. Another example is that if you ice skate you can watch the friction between the ice and your skate blades and see small tracks of water left in the ice. This is why ice skating is so slippery.
Friction can happen when there are the presence of gases as well. Anything that is entering into earth’s orbit, such as a meteorite or even a returning space shuttle, hits the atmosphere, which is made of gas. The friction that occurs between the solid object and the gas causes the generation of intense heat. That’s why the space shu