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| By Penubag (Own work) [Public domain], via Wikimedia Commons |
We've been learning about forces this semester. Often, we treat surfaces as "frictionless" to simplify calculations. When we talk about machines, we sometimes "neglect friction" and assume the machines are ideal. By doing these things, it's easy to associate friction with something bad. It is true that there are many situations where friction is not desired, and engineers usually take steps to reduce friction in their designs.
However, that's not the whole story. Sometimes friction in desired. What examples or applications can you think of where friction is "the good guy"? Post your ideas in the comments section.
An example where it would be a good thing to have friction would be a car. if there was no friction between the wheel of the car and the road, the wheel would just spin and the result would be no movement.
ReplyDeleteFriction would be the good guy when a pickup is trying to stop. The brake pads rubbing against the rotors creates friction and causes the truck to slow down. If the rotor and pad were frictionless the truck would not slow down.
ReplyDeletean example of where friction would be good would be when you are going up a slippery slope and don't want to slide back down. you want to have a lot of friction so that if you do start sliding down the hill, it would be slow enough that you wouldn't go very far.
ReplyDeleteI watched a movie recently in anatomy where a man fell off a cliff ledge and slid down a slope and almost off of the mountain. If it wasn't for friction, he wouldn't have stopped and survived. Also, in basketball you want more friction between the bottoms of your shoes and the court. You see players wiping the dirt off the bottom of their shoes so they get better traction and don't slip. Two points for friction (:
ReplyDeleteThere are some situations in the world where friction is desirable. One such case where friction is essential, is when a person is practicing their archery by firing at a target block. If there was no friction between the block and the arrow when the arrow impacted the target then the arrow would continue straight through the target block without being affected. In effect the archer would be down an arrow and without knowing where they hit. In this case friction is a good thing, since it slows down the arrow until it reaches a stop, giving the archer a precise test of their accuracy.
ReplyDeleteFriction is quite handy when you're on a slippery road while driving! If it wasn't for the bit of friction you do catch, we would certainly be in trouble. Another example is of when a person is clinging to a cliff face. If there was no friction between the rock and your hand, how would they stay on it at all?
ReplyDeleteI can think of many times when friction is the 'good guy.' One of these situations occurs when writing. The marks made by pens and pencils are caused by the friction between the writing utensil and the paper. Without friction, these methods of writing would not be able to be used! The same is true of chalkboards, markers, highlighters, and almost all other ways to write! Another prominent example in my mind is simply when a person holds or picks something up. Although the force of your hand wrapping around the object plays a large role, without the friction between your hand and the object, the object would fall through your hands and you wouldn't be able to hold on to it.
ReplyDeleteA situation where friction could be used to an advantage would be the game Tug-A-War. When you play this game, you have a team of people on each side.Each team holds on to the rope and pulls in opposite directions. The goal of this game is to pull the other team's half of the rope across the middle line. Friction is used not only to help the players stay in one spot; but also, to help the players keep their hands on the rope. Without friction this game could not exist and our high school pep assembly would not be as interesting!
ReplyDeleteAn interesting extension of this idea is sometimes done as a demonstration in physics classes... ... You have a "class" tug of war: girls vs. boys. The girls wear shoes and the guys take their shoes off. Who do you think usually wins? Why?
DeleteWell, there would be many variables to this experiment. Some of the variables might include; the floor type, the type of shoes the girls are wearing, whether the boys are in bare feet or in socks, and the number of people on each team. In a situation that we were playing in the gym, the girls had tennis shoes on and the guys were in socks; the girls could definitely win because the friction would be in the favor of the grip on the tennis shoes. This would be a good hands-on experiment to show friction and I think that we should try it in class sometime!!
DeleteI can think of a lot of reasons why friction is good. One example is fire. Without friction, fire wouldn't have been available. Food could never be cooked and people would have a harder time keeping warm. I also think of tires. Without friction the tires on your bicycle would never stop. Another example is walking. Without the help of friction we wouldn't be able to stay on our feet.
ReplyDeleteMost of these ideas are good, but I have a few questions. Are you saying fire cannot exist without friction? What about a lightning strike or a chemical reaction? Explain what you mean about cooking food. It's friction that cooks food? How?
DeleteFriction is good because it keeps us in contact with the floor while we are walking. Its good for brakes and car tires when driving a car also. In situations where you want to create heat friction is a good thing. We need friction because if we didn’t have it nothing would work properly, everything would be moving all the time, or unable to move, we wouldn’t be able to walk, sit in a chair, or eat or do any of the things that make up everyday life.
ReplyDeleteA good example of where friction is a good thing is when a automobile or motorcycle with modern disk brakes, using A brake rotor and brake pads normally made of ceramic and copper files comes into contact with the metal brake rotor causing friction between the two and slowing then slowing the vehicle down. If there was no friction between the two it would be near impossible to stop or slow down the vehicle.
ReplyDeleteFriction is the "Good Guy" in many everyday life situations. Some examples where friction is a good force is when you hit your breaks in a car, friction stops and slows you down. Friction is also a bonus in grinding down material or cutting wood or other stuff. Friction allows you to perform the cutting action. My last example that represents friction as good is when you walk or run, you need it in order to move yourself along the floor. Without friction in our lives, it would be very dangerous and annoying to be here on Earth. Friction deffinitly plays a key role in all our lives.
ReplyDeleteFriction is the "good guy" when in a car or riding a bike. If there was no friction then the car or bike would not be able to stop the car/ bike would simply keep going. Another example of friction being good is walking or running. With out friction there would be not traction it would be like walking on ice.
ReplyDeleteI think that almost everytime friction is the good guy, even in the example of a race car trying to reach top speeds although it may appear that friction is the bad guy slowing the car down. Friction is actually the good guy, however, because without it the car would not be able to start moving in the first place the tires would spin but the car would not move. It would be similar to when a person tries to run on ice. I think that while it is often beneficial to minimize friction no friction at all would be very bad.
ReplyDeleteI think friction is definitely the good guy. Without friction we would hardly be able to stop. Friction is neccessary for the world to run the way it does. Cars wouldn't people to stop or start moving and walking would be an enormous task.
ReplyDeleteit good when you stop a car.
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