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Grade Level: 8 (7-9)
Time Required: 45 minutes
Lesson Dependency:
What Makes Airplanes Fly?
Motion Commotion
Subject Areas: Physical Science, Physics
NGSS Performance Expectations:
| MS-PS2-2 |
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This engineering curriculum aligns to Next Generation Science Standards (NGSS).
Engineers use their understanding of the force of friction to design safe roads, tires, cars and brakes. Transportation and automotive engineers make sure that roads and tires provide the right amount of friction because friction provides traction and control for a safe driving experience, especially in icy or wet conditions. Even designing how paper is moved through a copy machine involves an understanding of friction. Engineers also reduce the force of friction between moving mechanical parts (in engines, tools, artificial limbs, etc.
) so the parts run smoother and last longer.
After this lesson, students should be able to:
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In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.
| NGSS Performance Expectation | ||
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MS-PS2-2. Plan an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object. (Grades 6 - 8) Do you agree with this alignment? Thanks for your feedback! |
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| This lesson focuses on the following Three Dimensional Learning aspects of NGSS: | ||
| Science & Engineering Practices | Disciplinary Core Ideas | Crosscutting Concepts |
Plan an investigation individually and collaboratively, and in the design: identify independent and dependent variables and controls, what tools are needed to do the gathering, how measurements will be recorded, and how many data are needed to support a claim. Alignment agreement: Thanks for your feedback! Science knowledge is based upon logical and conceptual connections between evidence and explanations.Alignment agreement: Thanks for your feedback! | The motion of an object is determined by the sum of the forces acting on it; if the total force on the object is not zero, its motion will change. The greater the mass of the object, the greater the force needed to achieve the same change in motion. For any given object, a larger force causes a larger change in motion. Alignment agreement: Thanks for your feedback! All positions of objects and the directions of forces and motions must be described in an arbitrarily chosen reference frame and arbitrarily chosen units of size. In order to share information with other people, these choices must also be shared.Alignment agreement: Thanks for your feedback! | Explanations of stability and change in natural or designed systems can be constructed by examining the changes over time and forces at different scales.
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High School Activity
Sliders (for High School)
In this hands-on activity, students learn about two types of friction — static and kinetic — and the equation that governs them.
They also measure the coefficient of static friction and the coefficient of kinetic friction experimentally.
Sliders (for High School)
Middle School Activity
Sliders
Students learn about two types of friction—static and kinetic—and the equation that governs them. They also measure the coefficient of static friction experimentally.
Sliders
Forces, Newton's laws of motion
Think about the last time you rode in a bus or a car.
Why do the wheels on some cars spin out at a green light, while other cars go forward without spinning wheels? Why do cars come screeching to a stop when the driver slams on the brakes? What makes a car going 60 miles per hour stay on the highway traveling safely forward? The answer to all these questions is the force of FRICTION (and Newton's laws of motion, of course)! Engineers need to understand the force of friction so that they can design safe roads, tires, cars and brakes. Engineers also try to reduce the force of friction between moving mechanical parts so that they will last longer.
When a car's tires start to turn, the friction between the road and the tires make the car begin to move forward. Similarly, when a car is going around a corner, the friction between the road and the tires keeps the car from sliding off the side of the road (remember Newton's first law? Without the force of friction, the car would tend to go in a straight line — straight off the road!) When a car slows down, the friction between the road and the tires helps to bring the car to a stop as the wheels slow down.
It is the friction between the wheels and the brake pads that causes the wheels to slow down. Obviously, friction is a very important force when you are riding in a car!
Imagine that there was a lot less friction between roads and tires. Pretend that there was the same amount of friction as there is between your shoe and ice if you walked across an ice-covered lake. What would happen? Cars would be slipping all over the road because the friction between the road and tire would not be sufficient enough to keep the tire "stuck" to the road. It would be hard for cars to start going because their wheels would spin. It would also be hard for the cars to stop. Imagine trying to stop a car by pushing on the brakes if there were no friction between the tires and the road — what would happen? Even if the wheels stopped turning, the car would keep sliding over the low-friction roads! The car would slide and spin out of control, going across the yellow line or into a ditch!
Sometimes, when it rains or snows, the friction between tires and the road can be greatly reduced, and there is the danger of the car sliding.
Because of this hazard, engineers developed extra safe brakes — computer-controlled antilock braking systems (ABS). Because these ABS brakes are computer-controlled, they can sense what each wheel is doing at all times. Since the computer knows what all four wheels are doing, if one wheel is about to start skidding while trying to brake, the ABS system can adjust the other three wheels so that the car does not slide. Refer to the fun and hands-on associated activity Hovercraft Racers! for students to investigate the friction between two surfaces. Follow-up with the associated activity How Far? Measuring Friction Using Different Materials for students to explore how different textures provide varying amounts of friction to objects moving across them.
Our imaginary low-friction road isn't all bad news, though. If a car could get going with very little friction between the tires and the road, the car would be much more fuel-efficient because the engine wouldn't have to work very hard to keep the car moving.
Transportation and automotive engineers make sure that roads and tires have the right amount of friction — too much, and the car engines would have to do more work to keep going; too little, and the cars would not stick to the road!
Engineers take advantage of this link between friction and tire/road dynamics to make roads with material that encourages friction for safety, but not too much friction, so that cars do not have to work too hard to move forward. In areas where there is a lot of snow, some people use special tires with metal studs because the metal studs poke into the snow and ice, creating more friction than rubber alone. Sometimes, roads are so icy that people even have to put chains on their tires to create enough friction between the car tires and the road so that they do not slip and slide all over the roads.
Following the lesson refer to the associated activity It Takes Two to Tangle to expand the idea of friction in personal relationships through stories.
Friction is a force that arises when things rub together. The frictional force between the road and tire is what allows the tire to "push" off the road, thus moving the car forward (Newton's third law — the action is the pushing frictional force, the reaction is the forward movement of the car). Imagine a car being lowered on a jack. When the tires don't touch the ground at all (and so there is no friction between the tires and the ground), the tires can spin, but the car does not move. At the very moment that the tires first touch the ground, they "grab" the ground. That "grab" is the frictional force between the tire and the ground. When the tires "grab" the ground, the car moves forward. Sometimes, such as when a car is on ice, mud or sand, there is not enough frictional force for a car's tires to grab the ground, and so the car has a hard time moving forward (it spins out or slides).
So, even though friction is often thought of as the force that opposes the motion of an object, the motion of a car would not be possible without friction! Friction may slow the car down as it moves along the road, but it also is the force that enables the car to move forward at all. It is the friction force that keeps the tires from sliding on the road. By the same token, it is friction that makes the car come to a stop when the brakes are applied. So, it is the force of friction that makes a car accelerate forward and also decelerate to a stop.
Friction is also very important when a car goes around a turn. If the friction between the road and tires is not sufficient, the car will slide sideways off the road instead of turning the corner. Dirt roads have less friction than paved roads, which is why cars sometimes slide around corners on dirt roads on TV or in movies. If cars are going very fast, the back tires can slide, making the car "fishtail" as it goes around the corner.
Have the students explain what they think friction is.
Why does it slow down movement, but at the same time make movement possible? Why is friction so important for engineers who build cars to understand? What are some additional applications of friction in day-to-day life and for engineers? What would life be like without friction?
Force: Something that acts from the outside to push or pull an object. For example, an adult pulling a child in a wagon exerts a force upon the wagon.
Friction: A force that arises when things rub together.
Newton's third law of motion: For every action there is an equal and opposite reaction.
Pre-Lesson Assessment
Discussion Question: Solicit, integrate and summarize student responses.
The friction between the road and the car's tires make it travel in the forward direction.).Post-Introduction Assessment
Question/Answer: Ask the students and discuss as a class:
Lesson Summary Assessment
Roundtable: Have the class form into teams of 3–5 students each.
Have the students on each team make a list of ways that friction affects cars by each person taking turns writing down ideas. Students pass the list around the group until all ideas are exhausted. Have teams read aloud the answers and write them on the board. (Suggestion: Friction does not only occur between wheels and the road — it also occurs between all moving parts in the engine, the brakes, etc.)
Friction Boggle!: Repeat the same activity as above, except when the teams read aloud their answers and write them on the board, ask if any other teams came up with the same idea. If any other teams have the same answer on their sheet, all teams have to cross that answer out on their list. The team that ends up with the most "unique" ideas, wins!
Ask the students go home and ride their bike, and return to school with some observations about the movement of the bike and friction that they've made while riding their bike.
How are road bikes different than mountain bikes? Why are the tires different?
Ask the students to research hovercrafts. How do they work? How fast can they go? What kind of surfaces can they go over? What role does friction play in the movement of hovercrafts?
Gittewitt, Paul. Conceptual Physics. Menlo Park, CA: Addison-Wesley, 1992.
Hauser, Jill Frankel. Gizmos and Gadgets: Creating Science Contraptions that Work (and Knowing Why). Charlotte, VT: Williamson Publishing, 1999.
Kagan, Spencer. Cooperative Learning. Capistrano, CA: Kagan Cooperative Learning, 1994. (Source for Roundtable assessment.)
VanCleave, Janice. Physics for Every Kid: 101 Easy Experiments in Motion, Heat, Light, Machines and Sound. NewYork, NY: John Wiley and Sons Inc., 1991.
Wolfson, Richard and Jay M. Pasachoff. Physics: For Scientists and Engineers. Reading, MA: Addison-Wesley Longman Inc.
, 1999.
The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.
Last modified: July 29, 2020
Back to Resources Natural Forces and Laws of Physics
Friction is the force that resists motion between two touching and moving objects or surfaces.
In addition to slowing down or stopping movement, friction also causes the moving objects or surfaces to heat up or make sounds.
Two types of frictions:
1. Static Friction
Static Friction is created when two objects are touching or pushing against each other without sliding.
For example, when you drive, your wheels push against the pavement causing the car to move, but there is no sliding of the tires against the pavement.
When you stop, your brakes create friction inside the wheels, which slows down the wheels, meaning your tires still push against the pavement, but in slower motion rather than sudden stopping (which causes sliding).
2. Kinetic or Sliding Friction
Kinetic or Sliding Friction is created when two objects are touching and sliding against each other.
For example, if you drive on a slippery road, or stop suddenly, your tires may slide against the pavement.
When your tires slide against the pavement, you will be more likely to lose control of your vehicle.
So for driving, you always want to be using static friction instead of kinetic or sliding friction.
When you drive, friction occurs between:
The following factors can affect friction as you drive:
Vehicle weight.
The heavier the vehicle, the more friction is created between your tires and the road; this means you will need more engine power to push forward, and it will be easier to stop the vehicle on a level surface road.
When your vehicle is heavy, the increased friction between the tires and road will heat up the tires. Thus, heavier vehicles will need tires that are more resistant to heat.
Braking.
When you apply your brakes, it causes the car's brake pads to touch the brake discs, which creates friction between the pads and discs; the friction causes heat and also resists the motion of the wheels and, therefore, slows down or stops your car.
Sudden Braking
If you suddenly apply your brakes, you will cause your wheels to lock and slide on the pavement (this is called losing traction and skidding).
You will not want your wheels to slide on the pavement because:
You will want your wheels to always turn on the pavement while driving or stopping because:
So, when gradually stopping, your wheels continue turning until the car comes to a full stop, which is the most efficient method, using static friction to stop the vehicle.
Anti-lock brakes prevents the wheels from locking and sliding and provide the operations of wheels turning while stopping – this way, the more efficient friction (static friction) is used to stop the vehicle; the vehicle will stop in shorter time and distance and you will have a better control of your vehicle.
Downhill Braking
If you are driving on an extended downhill stretch road (for a few minutes), you may need to shift to a lower gear to slow down your vehicle. This is because if you use your brakes consistently for a few minutes on an extended downhill, the friction created between your brake pads and brake disks (rotors) keeps generating heat, and your brake component can become too hot and lose the ability to absorb any more downhill kinetic force.
Over-inflated, worn out smooth tires or slippery road conditions
When your tires are over-inflated, your tires are worn out their treads and are smooth, or if the road is slippery due to ice, snow, rain, oil, sand or dirt, there is less gripping power between the tires and pavement and therefore, less static friction and more kinetic or sliding friction.
This creates the following problems for drivers:
Under-inflated tires
When your tires are under-inflated, there will be more static friction between your tires and the road. The increased friction will cause more heat between your tires and road and can cause more wear on your tires, and possibly tire tread separation or blowouts.
Does the braking distance generally depend on the width of the tires? ZR tests confirm: it depends! Although at first glance this statement may contradict the laws of physics.
Related materials
Tire test "Behind the wheel" - we measure the braking distance in heat and cold
This is a long-standing dispute between practitioners and theorists. The latter, as a reinforced concrete argument, cite dependence, which back in 1779was installed by the Frenchman Charles Augustin de Coulomb. It is familiar to many as a simple formula from a school physics course: F \u003d µN , where F is the static friction force, µ is the static friction coefficient, and N is the force of the normal reaction of the support, in our case, the pressing force of the wheel to the road. According to this formula, the maximum static friction force depends on the pressing force and the materials of the contacting surfaces.
There is no contact patch area in this formula, and hence the width of the tire tread! So, put any tire - wide or narrow - and the braking distance will not change?
Don't jump to conclusions. The dependence derived by Coulomb concerns only the force of static friction, which acts between two contacting bodies and prevents the occurrence of relative motion, that is, it is valid only if the wheels of the car are stationary (there is no rolling).
Imagine a car standing still on smooth asphalt. The driver presses hard on the brake pedal. The car is hitched to the tractor through a dynamometer that measures the traction force. The tractor starts moving, and the dynamometer records the value of the force that will be maximum at the moment when the car starts off with the braked wheels. If you perform such measurements by alternately installing sets of tires with treads of different widths, but from the same rubber compound, then the maximum force values will be similar.
In this case, Coulomb's law works ideally - the discrepancies of the obtained values will be minimal, within the measurement error.
But as soon as the car starts moving, the dependence established by Coulomb loses its relevance, because instead of the static friction force that keeps the slowed down car from moving, other friction forces will come into play. This means that other forces will act on a car that slows down (slows down).
Related materials
Tires by size: why pay extra for a low profile?
As you know, a moving body (for example, a car) has a kinetic energy equal to mv²/2 (where m is its mass and v is its speed). To stop the body, you need to rid it of this energy. The essence of the "classical" (without the use of recuperation) braking process is the conversion of the kinetic energy of the vehicle into thermal energy, followed by heat dissipation into the environment.
The more intense the heat is released and dissipated, the shorter the braking distance.
Braking (read: energy conversion) occurs due to the friction of the brake pads on the surface of the brake disc (drum), internal friction of the tread rubber (mainly when it is deformed in the contact patch), as well as tread friction on asphalt even with slight slippage.
Maximum braking performance is achieved when the wheel slip is around 15% (so-called service slip). On summer tires, this effect occurs due to a combination of internal friction of the rubber during tread deformation, shearing of fine fractions on the road surface, as well as energy absorption by the suspension - and is used during ABS operation, which allows slight slippage of the tire relative to the road. Thus, braking occurs in the transitional stage of sliding friction. It is necessary to go far beyond elementary physics to describe such a complex interaction of various types of friction. Moreover, the rolling present in this process contributes, continuously removing the “used out” heated tread area from the contact patch and delivering a fresh, colder one to it.
Friction inevitably leads to heating of the tread surface, and temperature changes significantly affect the grip properties of rubber. Overheating of the tread leads to a decrease in its strength and subsequent micro-destructions (melting) of the surface, further weakening the "hold". A typical example is braking on cars without ABS with full wheel lock, with smoke and a characteristic smell, leaving black traces of burnt rubber on the asphalt.
What do we have in practice? The wider the tread of the tire, the larger the area of its contact patch with the road, and hence the greater the friction surface. Therefore, more kinetic energy will be converted into heat. In addition, the dissipation of thermal energy will become more intense and the risk of overheating will decrease. All this together provides more effective braking.
Overcooling of the tire also has a negative effect on its grip.
This is especially evident from the deterioration in the results of "cold" braking on wet pavement at +6 °C (SR, No. 3 and No. 4, 2018). Rubber does not have the ability to warm up to operating temperature, and therefore remains insufficiently elastic and clings worse to asphalt micro-roughness. In this situation, the ability of wide tires to cool better, on the contrary, adversely affects performance - in cold weather, their grip deteriorates more noticeably than narrow ones.
Related materials
Brake pad test for Solaris and Rio: hotline
Very often the coefficient of friction is perceived as a kind of constant that determines the effectiveness of braking. In practice, this value is determined experimentally. Its physical meaning is the ratio between the friction force and the normal reaction force (this is the force that presses the wheel to the road). The force of friction depends on the characteristics of the rubbing surfaces. On the one hand, this is the condition and quality of the asphalt, on the other hand, the composition and characteristics of the rubber compound of the tire, the area of the contact patch and the distribution of pressure forces in it. In addition, the friction force is influenced by the temperature of the coating and air, humidity and many other factors.
It is noteworthy that the grip properties of any tires change during braking. In the initial period, they slightly improve as the rubber warms up to the most effective (working) temperature, and then, if the rubber compound does not have time to give off heat and overheats, they may worsen.
How to calculate the coefficient of friction? According to the formula k \u003d v² / 2gs (where v is the deceleration start speed, g is the free fall acceleration, s is the stopping distance). The value of the braking distance for each tire is obtained experimentally - we measure it when braking on asphalt.
Different tires provide different braking distances - therefore, they differ from each other in their grip properties. Moreover, the wider the tread, the better the grip properties (of course, if the rubber mixture is not supercooled). Our tire test results prove it. And, as you already understood, they do not contradict the laws of physics.
Many drivers are probably familiar with the situation when some animal suddenly runs out onto the road, for example, a cat, a dog, etc. Agree with us, quite an unpleasant moment. After all, the driver has only a fraction of a second to react to this situation. At this very moment, most of the drivers will definitely press the brake pedal, confident that their car will start to stop almost instantly.
But why are we one hundred percent sure of the brakes of the car? I would like to know how the brake system works in a car? Let's get together friends with you now find out how these brakes use science to stop a heavy car.
In front of you friends is a parachute brake that reduces speed and kinetic energy so that a pilot who has ejected from an airplane or from a simulator landed safely on the ground.
energy. Kinetic energy is the energy that a particular object possesses because it has mass and velocity (speed in a particular direction). The more mass there is (that is, the heavier the object) and the faster you or the object moves, the more kinetic energy you or the object will have.
All this is of course good, but what if you suddenly need to stop? How to go from fast movement to the state of not moving at all. To do this, you or the object needs to get rid of its kinetic energy.
For example, if you are jumping on the spot from a flying aircraft, then the best way to lose energy for you is to parachute. Thanks to the giant "cloth bag" that flies after you, the movement slows down, that is, the falling speed decreases, and therefore the parachute helps you get rid of your own kinetic energy.
As a result, the parachute allows you to safely and smoothly land on the ground unharmed.
By the way, powerful dragster cars, which are champions in acceleration from a standstill and with them sports cars that can accelerate to record speeds, also use parachutes to stop them. But most ordinary cars, as you know, use the traditional hydraulic braking system, which was invented back in the early 20th century, to stop and slow down.
In cars, trucks, airplanes and the same trains, the brakes work in general and in principle the same way. In our world, there are many other modes of transport that are also provided and equipped with similar types of braking.
There are brakes, oddly enough, even in wind turbines. Here is a brief comparison with each other of some common braking systems in the world:
If you use and ride a bicycle, you certainly know that you have nothing to fear when accelerating, because at the right moment, when you want to stop, you will use the brake provided in any bicycle transport. Usually, to do this, you press the brake lever on the handlebar and the bike starts to slow down, and this happens due to the fact that the metal cable coming from the brake lever pulls small calipers located directly on the wheel, thereby forcing the thick rubber blocks to press against it. to the wheel. At this point, friction is created between the brake rubber blocks and the metal rim of the wheel. As a result of this friction, heat is created and released, and at the same time, the kinetic energy of your bike begins to decrease. As a result of this, you will safely stop.
The brakes on a steam locomotive work exactly the same as on a car.
In the photo, you friends can see a locomotive brake. It clamps on the driving wheels of the locomotive to slow them down. But how does the train stop if there are no rubber tires on the wheels themselves? After all, friction is necessary, including with the road surface, to stop?
It's very simple. Since the locomotive has a huge mass and its wheels do not have rubber, this friction in a railway locomotive is created precisely because of the huge weight that directly presses on the wheels, which are pressed against the metal rails. As a result of such friction of metal wheels with metal rails, a large amount of heat is generated and released, which reduces the kinetic energy of this moving locomotive.
Motorcycles (motorbikes) usually have disc brakes in their design, which contain brake discs, a caliper and the same brake pads. The brake disc, as a rule, has holes (or grooves) over the entire area. The principle of operation of the brakes in a motorcycle is quite simple, that is: - the brake shoe itself is clamped with a cable, which, like on a bicycle, can go to the steering wheel or directly to the foot pedal.
As soon as the motorcyclist presses the brake pedal or the brake lever, the cable immediately begins to press the brake pads against the brake disc. The holes in the brake disc help dissipate the generated frictional heat.
In aircraft, the brakes are installed directly inside the wheels themselves. This helps the pilot stop the plane on the runway. Also in aircraft technology, air brakes can also be used, which increase air resistance, which ultimately slows down the aircraft during its flight. And the plane can also slow down due to the reverse thrust of its engines, if the pilot turns on the so-called reverse.
As we told you above, wind turbines also have a braking system inside them. They need it to prevent and slow down too fast rotation of the rotors (propellers). Most wind turbines have an anemometer that measures wind speed. If the wind speed rises above a safe level, then the brake is automatically activated immediately, which leads to a slowdown in the rotation of the propellers or to their complete stop.
Well, the high wind speeds mean that, if possible, much more of the required energy could be obtained from these wind turbines than is received today. But safety always comes first.
Automotive brakes in their early days were remarkably primitive by today's modern standards. Here in front of you friends is a very simple friction system invented and created by the American John Stawartz at 1910 year.
When you press the brake lever (indicated in yellow in the picture), a huge brake shoe (in blue) drives under the rear wheel of this vehicle (indicated in brown).
Essentially, the car sits on a block-shoe whose teeth mesh directly with the road surface, causing the car to slow down and eventually stop.
Most vehicles have two or three different types of brake systems. Point your friends to the front wheels of your car. Just behind the rim you will see the brake discs.
When the driver presses the brake pedal, brake pads made of wear-resistant material immediately begin to clamp on both sides of the brake disc.
As a result of the friction of the pads with the brake discs, heat begins to form and release, and at the same time the kinetic energy of the car itself decreases, which, as a result of all this, begins to slow down. As you can see, it's the same principle as motorcycles and even bicycle brakes.
0002 Some car brands also have disc brakes on the rear wheels. But many cars still have drum brakes on the rear wheels, which work a little differently than disc brakes. Instead of the disc itself, such brakes use a brake drum inside which, in a hollow area, brake pads are installed, which, with the help of springs and brake cylinders, when the driver presses the brake pedal, begin to press against the very surface of the drum.
The vehicle's handbrake brakes and acts on the rear wheels. This handbrake is activated by a lever located inside the machine.
True, compared to pressing the brake pedal, this handbrake is less effective and weaker.
A rapidly accelerating car has a lot of energy, and when you apply the brakes (whether drum, disc or hand brake), this energy is converted into heat as a result of the friction of the brake pads with drums or brake discs.
Naturally, drums and brake discs can heat up to 500 °C or more due to high friction! This is why drums or discs must be made of materials so strong that they won't melt at high temperatures. For example, expensive metal alloys, as well as composites or ceramics, are ideal for the manufacture of brake discs, drums and brake shoes.
Before you friends picture description: -When your foot presses the brake pedal, the brake fluid in the brake system is squeezed out and directed from a narrow cylinder to a wider cylinder. Such a system is known to many under the name of a hydraulic system.
This allows you to significantly increase the strength of your braking force.
Imagine the following, how much personal strength would be required for you to stop, for example, a fast car... Simply pressing the brake pedal could not create enough force to activate all four at once brakes in such a way that you can calmly stop your car at a fast pace. That's why brakes use hydraulics, namely a system of tubes filled with brake fluid that increase your braking power. Also, thanks to this hydraulics, braking forces can be transferred easily from one place to another in a short period of time.
When you step on the brake pedal, your foot is essentially moving a particular lever at the same time, which causes the piston in the long, narrow brake cylinder (the brake master cylinder) to move, which in turn begins to further move the hydraulic fluid ( brake fluid) towards the narrow tube that is located at the end of the brake cylinder.
Connected to this tube are, as a rule, other tubes of the same diameter that go to each car brake. Further, the brake fluid through narrow tubes enters directly into larger cylinders, which are located on the wheels.
Since the brake cylinders located at each wheel are much larger than the cylinder itself, which is located in the brake system immediately after the brake pedal, the force that you initially applied to the brake pedal is greatly increased. As a result, this same force begins to compress the brake pads in each individual wheel brake.
As the piston moves inside the cylinder, it begins to compress the brake fluid and pushes it into a narrow hole, which is located at the end of the cylinder to which the tube is connected. This is much like how a hand pump squeezes and directs air from a cylinder into a thin hose.
Our simple example shows the basic working principle of this and similar hydraulic brake systems. Well, in practice, things are a little more complicated.
In fact, the brake pedal actually controls four separate hydraulic brake lines going directly to all four wheels. In our example, we show you friends the principle of the brakes on only one wheel of the car (you know that there are four of them).
For safety reasons, all vehicles generally have two separate hydraulic brake circuits. This is necessary in case, due to some kind of malfunction, one of the two brake circuits suddenly fails.
