Jason Fry
Constance Nelson
Composition I 30127
29 June 2015
The Physics of Stopping: A Brief Tutorial
Anyone who has been driving for any significant amount of time has had that moment. Driving down the road minding your own business, when suddenly in front of you a chicken is crossing the road. You slam your foot onto the brake pedal, bringing the car to a stop with inches to spare. The chicken goes about its business completely oblivious, safely making it to the other side of the road. Heart pounding, you carry on with your drive, shaking your head at the close call and the chicken’s lack of judgement in choosing this particular moment to cross the road. Your brakes worked flawlessly, arresting the motion of a multi-ton object traveling
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While much greater than the force you have applied, it is still not nearly enough to stop a car. There is another factor in the system on modern vehicles, called a booster. This is basically another hydraulic circuit, except it uses vacuum from the engine instead of fluid, and it “boosts” the amount of force applied by the pedal to the hydraulic part of the brake system, rather than multiplying it. Usually around 300 to 400lbs of additional force is generated by the booster. Adding this to the equation, the driver applies 10lbs of force to the pedal, which is multiplied to 20lbs through the mechanical advantage of the pedal ratio of 2:1, this is “boosted” to 420lbs, and multiplied by the hydraulic circuit at a ratio of 9:1 to generate a pressure of 3780lbs at the brakes. As you can see, a booster makes a huge difference in the equation. If you have ever driven a classic car without power brakes, you know that to stop you have to apply much more pressure to the pedal, than you would with a modern car and a boosted system. In this case, to stop in the same distance from the same speed, the driver would have to apply 210lbs of force to the …show more content…
The final part of the braking system is one that is easy to overlook, a lot of people don’t associate with braking at all. The tires. Tires are, as a major brand’s advertisment says, “the only safety feature on the road that actually touches the road.” Stopping the brake rotors, and thus the wheels and tires does little good, and is usually of some detriment if trying to make a controlled stop. This is because when the tires stop moving, or “lock up” their grip on the road changes because the static friction between the tire and the road changed to dynamic friction. The easiest way to imagine this is if you were trying to push a heavy box across the floor. While the box is stationary there is static friction between itself and the floor, once it starts to move it becomes dynamic friction. You might have noticed before if you have ever tried to slide something heavy that it takes more effort to get the object to move initially, than it does to keep it moving. This is because static friction takes more force to overcome than dynamic friction. Similarly, once the tires are sliding on the road, there is less friction, and thus a reduction in braking force relative to the vehicle and the road, not to mention the possibility of spinning out of control. The tires gripping the road is what actually slows the vehicle down and brings it to a controlled
Eighteen wheelers are a vital part of interstate commerce in our country. The big rigs carry products across state lines, and keep our stores’ shelves stocked with the things we need on a daily basis. But, when a trucker is involved in an accident, the injuries are usually catastrophic. The sheer weight of a truck is such that when it collides with a car, the results are severe. Drivers and passengers in cars can suffer broken bones, internal organ damage, spinal and brain cord injuries, or even death. Staying safe around big rigs requires drivers to pay extra special attention when near a truck, and to keep a safe distance. But, drivers can only do so much; it also takes diligence on the part of the trucker in order to safely share the road.
It is always important to keep in mind the requirements of the vehicle you are driving. If you have a larger vehicle, you may want to begin slowing down quicker than you would if you were driving a small car. This is because your vehicle has more mass and more energy is required to stop it. However, if you are driving a small vehicle, you may want to slow down a bit later than you would if you were driving a smaller vehicle so it has enough momentum to make the
As a new driver, I am constantly worried of hitting other objects such as cars, mailboxes, and animals. When deer jump out from the side of the road, I worry that they may cause deadly accidents. Gorman’s article interested me because if there is
Very few people wake up in the morning hoping they will crash into a tractor-trailer during their morning commute. It is unimaginable and scary to consider a collision with a tractor-trailer or an 18-wheeler truck. Collisions happen often. Even though statistics show that 3% of road collisions involve large trucks, that’s still over 450,000 accidents every single year. This can happen to you whether you’re a teacher in the Erlanger-Elsmere school district, an apartment manager at Saratoga Place, or a member of the 7 Hills Church.
The stopping distance, oftentimes called braking distance, is the distance that a car travels while slowing to a complete stop. There are many variables that affect the braking distance that one should consider while driving to insure that there is enough room to come to a complete stop without a collision. The slope of the road is a variable that affects the braking
The reason for the development of anti-lock braking system is very simple. Under braking, if one or more of a vehicle’s wheels lock then this has a number of consequences: a) braking distance increases, b) steering control is lost, and c) tire wear will be uncommon. The tangible outcome is that an accident is more likely to occur. The application of brakes creates a force that impedes a vehicles motion by applying a force in the opposite direction. During severe braking scenarios, a point is obtained in which the tangential velocity of the tire surface and the velocity on road surface are not the same such that an optimal slip which corresponds to the maximum friction is obtained. The ABS controller must deal with the brake dynamics and the wheel dynamics as a whole plant.
Performance: Regenerative braking can enhance the driving experience by giving you the smooths drive of your
Therefore, hydraulics were added into the system because many other brake designs failed and caused the hydraulic brake idea too soon be built. But as roads improved and other transportation vehicles were increasing their speed on the roads, engineers realized the need for a better braking system. Hydraulic brakes have also affected the world in many ways, such as the idea that hydraulic brakes became more effective in stopping a vehicle than drum brakes, making hydraulic brakes safer and easier to handle. But since the hydraulic brakes helped prevent accidents over the course of time, it became a requirement that all cars sold in the U.S. had to include two hydraulic circuits. Hydraulic brakes have become very important over the years and
In this report a comparison of three Braking systems; Calliper, Drum and Disc will be made on a variety of areas including –
When people learn to drive sometimes it is hard to try and stop in time. Most people can do it but others have a tough time when they are not paying attention to what is going on around them. Braking distance is traveled before coming to a complete stop.
In today’s world, many drivers have become complacent in the fact that the vehicle in which they are operating can be a deadly weapon. A two-ton hunk of metal flying down the freeway at speeds excess of seventy miles an hour carries much potential for catastrophe.
Faulty brakes can lead to serious risk of injury or accident, but many car owners are poorly equipped to handle routine brake issues with their cars. If you act quickly when these problems first start to show symptoms, you may be able to keep the damage and repair costs to a minimum. Luckily, it may be possible to avoid major problems with your car’s brakes by following these maintenance and repair tips.
Anti-lock braking system, or ABS, is a device that assists cars to slow down on a slippery surface in emergency situations while still allowing the car to be steered. When a driver hits the brakes and the tires start to lock and lose their grip on the road, the friction between the tires and the road decreases. The tires are fighting against static friction to keep the car in motion. When the wheels are sliding over the road they are continuing
Technology has influenced my life in many ways this past week. One major influence has been brakes on my car. I have very bad brakes on my Honda Civic and I don’t quite have the money until later this week to get them fixed. However, brakes on cars help stop a vehicle from running into other cars or pedestrians. Without brakes it would make the use of vehicles difficult. We have a stop and go petal used to maintain speed. The brakes is controlled by your leg and foot used to decrease friction. One of the terrible parts about brakes is they need to be changed if over use.
It must be noted that cars are dangerous vehicles which can cause fatal damage. Individuals responsible for a vehicle are expected to be more alert than pedestrians walking down the street or crossing the road, this is known as “destructive disparity”. This