The shape of a typical airplane wing is called an airfoil. This shape, which is smooth, narrow, rounded, and sleek, passes through the air easily.
It has a very low drag coefficient — 0. On the other hand, imagine if an airplane had sharp-edged, boxy, prism-shaped wings. These wings would generate much more friction because they wouldn't pass through without great resistance.
In fact, prisms have a higher drag coefficient than airfoils — about 1. Objects with bigger, boxier "body flows" generally generate more drag than other objects. On the other hand, objects with streamlined body flows are narrow, have rounded edges, and usually taper off towards the back of the object — like the body of a fish.
Use a less permeable material. Some types of materials are permeable to fluids. In other words, they have holes in them that the fluid may pass through. This effectively reduces the area of the object that the fluid is able to push against, lowering the force of drag. This property holds true even if the holes are microscopic — as long as the holes are large enough to let some of the fluid pass through the object, the drag will be reduced.
This is why parachutes, which are designed to create lots of drag to slow the speed of the user's fall, are made out of strong, light silk or nylon and not cheesecloth or coffee filters. For an example of this property in action, consider the fact that a ping pong paddle can be swung faster if a few holes are drilled in it.
The holes let air pass through as the paddle is swung, greatly reducing the drag and allowing the paddle to move faster. Increase the speed of the object. Finally, no matter what shape an object is or how permeable the material it's made from is, the drag it creates will always increase as it goes faster.
The faster an object goes, the more fluid it has to move through, and, thus, the greater drag it experiences. Objects moving at very high speeds can experience very high friction due to drag, so these objects usually must be very streamlined or they will fall apart under the force of the drag.
For instance, consider the Lockheed SR "Blackbird", an experimental spy plane built during the cold war. The Blackbird, which could fly at speeds greater than mach 3. Did you know you can get expert answers for this article? Unlock expert answers by supporting wikiHow.
Bess Ruff, MA. Support wikiHow by unlocking this expert answer. Not Helpful 10 Helpful 7. The faster an object goes, the more matter gas or liquid it has to move through, and thus, the greater drag it experiences. Not Helpful 13 Helpful The three methods of increasing friction are: 1. By applying more force to the object, 2. By increasing the mass of the object that is causing friction, and 3.
By creating a rougher point of contact. Not Helpful 12 Helpful More grain to a surface typically increases friction. This is why people make sure boats and planes are as smooth as possible. Not Helpful 7 Helpful Sandpaper and rough stone would increase friction. Generally, there is more friction when a surface is rough rather than smooth. Not Helpful 10 Helpful Jonathan Ogutu. To increase the amount of force that is being used simply increase the amount of pressure you apply when interacting with the body.
Not Helpful 5 Helpful Michael Wang. Frictive, according to Wiktionary, means "Of, relating to, or caused by friction. No, it doesn't but it will help to decrease friction so your making the rough surface smooth. Rough surfaces increase friction while smooth surfaces decrease it. Not Helpful 4 Helpful To decrease friction, you can make the surface smoother, make the objects more streamlined, or reduce the forces acting on the surfaces.
Include your email address to get a message when this question is answered. Extremely high friction can release lots of energy in the form of heat! For example, you won't want to touch a car's brake pads right after you've slammed on the brakes! Helpful 1 Not Helpful 0. High drag forces can cause structural damage to an object passing through a fluid. For instance, if you stick the flat side of a thin piece of plywood into the water while you're cruising in a speedboat, there's a good chance it will be shattered.
Helpful 0 Not Helpful 1. Related wikiHows How to. How to. About This Article. Do this a few times to compact the rice and get rid of the air pockets. Now you should have room to add a bit more rice to the bottle. Once you've added a bit more rice, stick the chopstick back into the bottle. This time, when you pull up on the chopstick, you should be able to pick up the whole bottle.
Fig: Holding up a bottle with just a chopstick Concept : Friction applied by rice on the chopstick. Quiz Time 1. Define friction, and explain why it occurs. Identify three factors that affect friction. Why does friction warm your hands when you rub them together?
Outside wooden steps may get slippery when they are wet. How could you make them less slippery? Types of Friction Friction is the force that opposes motion between any surfaces that are in contact. Static, sliding, and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases.
Static Friction Static friction acts on objects when they are resting on a surface. For example, if you are hiking in the woods, there is static friction between your shoes and the trail each time you put down your foot see Figure below. Without this static friction, your feet would slip out from under you, making it difficult to walk.
In fact, that's exactly what happens if you try to walk on ice. That's because ice is very slippery and offers very little friction.
Can you think of other examples of static friction? One example is the friction that helps the girls climb the rock wall in the picture above. Static friction keeps their hands and feet from slipping. Sliding Friction Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction.
That's why it's easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example, you use sliding friction when you write with a pencil. The pencil "lead" slides easily over the paper, but there's just enough friction between the pencil and paper to leave a mark.
How does sliding friction help you ride a bike? There is sliding friction between the brake pads and bike rims each time you use your bike's brakes. This friction slows the rolling wheels so you can stop. Rolling Friction Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards.
Ball bearings are another use of rolling friction. You can see what they look like in the Figure below. They let parts of a wheel or other machine roll rather than slide over on another. The ball bearings in this wheel reduce friction between the inner and outer cylinders when they turn. Fluid Friction Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container.
Fluids include liquids and gases. If you've ever tried to push your open hand through the water in a tub or pool, then you've experienced fluid friction. You can feel the resistance of the water against your hand.
Look at the skydiver in the Figure below. He's falling toward Earth with a parachute. Resistance of the air against the parachute slows his descent. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. That's why there is greater air resistance against the parachute than the skydiver's body. Fun with Friction: Activity 1: Take a few pencils which are cylindrical in shape.
Place them parallel to each other on a table. We need to increase the irregularity in the surfaces in order to achieve high friction. This can be achieved by texturing surfaces with designs or etching the surface using harsh chemicals.
The fine fingerprints in our finger increase friction and enable us to hold on to objects. Normal force force in the direction perpendicular to the sliding surface will result in the surface coming closer together and hence the interlocking of the irregularities in the surface becomes stronger and hence friction is increased in the process.
We can increase this normal force by 1. Sometimes when we sweat, it is very difficult to hold anything, things slip off our hands this is because our sweat works as a lubricant here and reduces friction between our hands and the surface.
You can wipe the sweat off to increase friction. Removing wheels is the best option to increase friction in the surface where rolling friction is involved.
Sliding friction is always greater than rolling friction. In a hilly area, friction becomes a very important factor. The higher the friction the better will be the grip of the vehicle on the road.
We can increase the friction in such cases by having tires that have more textures on them specifically built for such roads. Sometimes chains are used to increase friction, especially in snowy terrains. Home Animation Quiz. Sign in.
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