Friction is the force that causes the impeded movement of an object. Friction is everywhere, when one object comes into contact with another there is friction. The force acts in the direction opposite to that in which the object is pushed, pulled, or rotated. When a car is at a stop sign, it has stopped due to friction between the brakes and the wheels. If you're running along the sidewalk and want to stop quickly, you can because the friction between your shoes and the concrete allows it. What happens if you are running down the sidewalk and try to stop on a wet surface? Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The friction is still present, but the liquid makes the surfaces smoother and the friction much less. Less friction means it's harder to stop. Low friction occurs in vehicles on a rainy/wet day. This is why so many accidents often occur. The brakes still have friction but it is limited, both the wheels and the brakes may be wet preventing the normal braking process. Cars hydroplane/drift when they go too fast over puddles of water. Friction can only occur with solid objects, but in liquids and gases there is still resistance but no friction. This doesn't involve sliding surfaces like friction does, but is instead the kind of resistance you get if you try to push your way through a crowd. This is because two surfaces/objects have. If the gas is air, it is called air resistance. If you were in the space shuttle and re-entered the atmosphere, the bottom of the shuttle would get very hot. The collisions that occur between the molecules of the air compressed by the shuttle heat the air and the shuttle itself. The temperature at the top of the shuttle is also warm, but far from the temperatures found at the bottom. While liquids offer resistance to objects moving within them, they also smooth surfaces and reduce friction. Liquids tend to become thinner (less viscous) as they are heated. This is similar to the viscosity of the oil you put in your car. Car engines have many moving parts and rub against each other. Rubbing produces friction and the result is heat. When you add oil to a car engine, the oil sticks to surfaces and helps reduce the amount of friction and wear on engine parts. An engine that runs at higher temperatures requires a more viscous oil to properly adhere to surfaces. Please note: this is just an example. Get a custom paper from our expert writers now. Get a Custom Essay Friction measurements are based on the type of materials in contact. Concrete on concrete has a very high coefficient of friction. This coefficient is a measure of how easily one object moves relative to another. When you have a high coefficient of friction, you have a lot of friction between materials. Concrete on concrete has a very high coefficient and Teflon on most things has a very low coefficient. Teflon is used on surfaces we don't want things sticking to; like pots and pans. Scientists have found that there is even less friction in the joints than in Teflon! It's another example of how efficient living organisms can be.