# Car Definition and 76 Discussions

A car (or automobile) is a wheeled motor vehicle used for transportation. Most definitions of cars say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people rather than goods.Cars came into global use during the 20th century, and developed economies depend on them. The year 1886 is regarded as the birth year of the modern car when German inventor Karl Benz patented his Benz Patent-Motorwagen. Cars became widely available in the early 20th century. One of the first cars accessible to the masses was the 1908 Model T, an American car manufactured by the Ford Motor Company. Cars were rapidly adopted in the US, where they replaced animal-drawn carriages and carts, but took much longer to be accepted in Western Europe and other parts of the world.Cars have controls for driving, parking, passenger comfort, and a variety of lights. Over the decades, additional features and controls have been added to vehicles, making them progressively more complex, but also more reliable and easier to operate. These include rear-reversing cameras, air conditioning, navigation systems, and in-car entertainment. Most cars in use in the early 2020s are propelled by an internal combustion engine, fueled by the combustion of fossil fuels. Electric cars, which were invented early in the history of the car, became commercially available in the 2000s and are predicted to cost less to buy than gasoline cars before 2025. The transition from fossil fuels to electric cars features prominently in most climate change mitigation scenarios, such as Project Drawdown's 100 actionable solutions for climate change.There are costs and benefits to car use. The costs to the individual include acquiring the vehicle, interest payments (if the car is financed), repairs and maintenance, fuel, depreciation, driving time, parking fees, taxes, and insurance. The costs to society include maintaining roads, land use, road congestion, air pollution, public health, healthcare, and disposing of the vehicle at the end of its life. Traffic collisions are the largest cause of injury-related deaths worldwide.Personal benefits include on-demand transportation, mobility, independence, and convenience. Societal benefits include economic benefits, such as job and wealth creation from the automotive industry, transportation provision, societal well-being from leisure and travel opportunities, and revenue generation from taxes. People's ability to move flexibly from place to place has far-reaching implications for the nature of societies. There are around 1 billion cars in use worldwide. Car usage is increasing rapidly, especially in China, India and other newly industrialized countries.

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1. ### I How to transfer angular momentum between two flywheels?

I am trying to build a simulation of a car engine and wheels for a game project. My model is currently this: Engine outputs a torque -> this spins up a flywheel over time (the physics step of 1/60s) -> the flywheel is coupled with the clutch and thus transmission -> the transmission multiplies...
2. ### Modeling torque on a half car model

Imagine an half car model with the two suspension and two wheels. There is a torque applied to the rear wheels, that torque create the force between tire/asphalt that pull the car. How that torque react in the main body? I have two hypotesis: 1) It's only internal force that tend to bend the...
3. ### Car reading 17V+ in the battery when running, how to fix?

Hi, I have a 2004 Toyota Matrix with 270 000km. It's working great but today when i started my car the battery was going up to 17.2V (i have a battery voltage reader in the car at all time). It's the first time it went up there, it usually stays in the 13-14V. I know something is wrong and I...
4. ### Question about multimeter continuity

Hi guys , i am working in the automotive industry today i encountered a weird electrical issue and i am sure you guys have an explanation , i was using my multimeter to check continuity between different stuff , by mistake i put the leads on the car battery terminals i found the multimeter...
5. ### How to calculate each car tyre load during cornering?

This is about vehicle physics. I know how to calculate weight on each axle on a car during deceleration. Given the picture below: The weight on the front axle is calculated as: Wf=(c/L)*W-(h/L)*M*a and the weight on the rear axle is calculated as: Wr=(b/L)*W+(h/L)*M*a where c and b are the...
6. ### How to produce a harmless gas in seconds? (for an emergency car floatation device)

I need to make the design of car floatation devices. In my case, the airbag/raft is for floating the car in case of floods. I am considering to use Sodium Azide, just like in car airbags, but it inflates very fast and shrinks in a short time. Is there any other chemical reaction that can produce...
7. ### A few questions on car mechanisms and driving habits

I have a Toyota Etios Liva, about three and a half years old. It is a petrol variant, with manual transmission. I am quite interested in the mechanisms of a car and good driving habits. Sadly, none in my family knows driving. My knowledge of driving habits extend to the manual given with the car...
8. ### Automotive Hydrogen Car Fuel Tank

How do hydrogen powered cars prevent the permeation of hydrogen through the valve used to fill the car's tank with hydrogen? Is a regular check valve used or is the valve special in some way?
9. ### How to use my data of Ixx, Iyy and Izz?

Hi everyone, thank you for reading my thread I know the question is weird but I can't seem to explain it otherwise. My problem: Basically I am finishing a final year project which I based on a Formula Student Vehicle. Using CAD I have the vehicle modelled, and through the model analysis and...
10. ### Car's braking distance formula

Hello everyone ! I'm working on my highway code and my book give me the approximate formula and the real formula of the braking distance. Here's the real formula according to the book : $$Bd = \frac{V^2}{254 \times f}$$ With : V : the velocity f : the adherence coefficient. But I have on...
11. ### Can you damage your starter motor with too much current?

Hey all! Today I took my car to the shop for some starter issues. They told me that the starter had been damaged by a battery with a higher CCA rating than was safe for the starter motor and it burned out my motor slowly over time. I feel like they may be BS'ing me, but I'm not sure. I know my...
12. ### Relation between centrifugal force and speed

Does centrifugal force generate in increase in overall speed? For example, if I am driving down a highway on-ramp which goes in a circular fashion, with my speed slowly increasing, does my overall speed increase because of the centrifugal force generated from the circular on-ramp? Is more force...
13. ### Accelerating a car including the moment of inertia of the wheels

Homework Statement A car accelerates from rest on a horizontal surface. The engine provides a torque of τ = 200 Nm on each of the two front wheels. Each of the four wheels on the car weigh m = 15 kg, have radius R = 0.35 m and can be considered solid, uniform discs. The rest of the car (not the...
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### Automotive Construction of CVT Metal push belt

I am trying to understand the construction of CVT Metal belts that are made up of steel elements and some rings. I do not understand the full construction details of the belt. The most detailed information I have got ever is in this PDF on page 5...
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### Questions involving airflow and pressure around a car

Homework Statement 1.Since the roadster seats only two people, it has only two side windows--one on each side. Each window is aligned squarely on the vehicle, so air can flow straight past the window as the vehicle heads forward. However, the air flowing around the roadster's windshield has to...
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### Why do we need a switch before a relay?

So in high current circuits which involve say a starter motor in a car we need a starter relay since a normal switch cannot handle the high current flow. I think the reason I'm asking this question is because I don't understand what exactly makes the relay be able to handle the current unlike...
17. ### Automotive Flying Hypercars?

Recently the Bugatti Chiron set a record of some sort for rapidly accelerating to 249 mph and then dropping back down. The engine is something to the effect of 1500 horsepower and the vehicle isn't terribly heavy. Old Airplanes had engines below 400 horsepower and ultra lights can be far less...
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### 4WD Arduino Controlled car - Problem with motor shield

I've been working with what will be a small Arduino 4WD controlled car, however now I've found a problem. The motor shield I used is an Arduino UNO motor shield R3, v3, which means that it can only control 2 motors, howerver I'll be using 4. Is there any way to use this same shild but apply all...
19. ### Speedometer working principle

I'm wondering how does speedometer work. To be specific lets talk about car speedometer. I googled it and found out that there are different kind of speedometers, but not quite understood it's working principle. My question is not about how it shows us speed (Mechanically with arrow or...
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### Automotive Car downforce: accelerating air under the car vs blocking

As most of you know real racecars have flat bottoms, rear diffusers and in the front well... a variety. So to keep this simple. I am building a car with a flat bottom and rear diffuser, car raked at 4 deg, diffuser at 14 (all details will be adjusted based on learned info) and nothing on top or...
21. ### Automotive Friction force, Coefficient of friction &Traction

I have few (more or less) general questions: 1. I know that: "The coefficients of friction are nearly independent of the area of contact between the surfaces". I understand this, but I know from everyday life, when car tire tread is worn off, braking distance increases and maximum acceleration...
22. ### Simple and clear LED question. LEDs pop and break

Attached is a picture of my set-up. It is very simple and if for a car (12V) The LED kit comes with 3 options: Hard wire install, cigarette lighter install, and 9 + 9 V battery demo. The peculiar thing is when I connect the hard wire install plug (shown at the top of the picture) to a...
23. ### Question about friction? Dynamics

Homework Statement This is the problem http://imgur.com/a/1XFlt 2. Homework Equations This is the given FBD http://imgur.com/a/CURqA 3. The Attempt at a Solution Now the car should have a tendency to slip down the ramp thus causing the frictional force to oppose this motion. But the...
24. ### Automotive Traction and friction

Hi, I'm simulating the behavior of a car and I have some troubles with the tires. Specially with slip when the car is accelerating. I've seen many documents over the internet and I understood 2 main things: Wheel slip is necessary to accelerate & the coefficient of friction depends on the slip...
25. ### Is the car accelerating?

As I was driving I was wondering if there is way to know if the other cars on the road accelerating. I think that if I were travelling at a constant, then if the rate at which the distance my car and another car was changing was not constant, then the other car would be accelerating. But is...
26. ### Friction and turning angle relation

Hi there, Suppose we had a car going in a circle. We know that the turning angle(angle between the movement direction and the wheel axis) and the friction are connected, because friction determines the centripetal force and it determines the radius of the circle that we make with our car. I need...
27. ### Can a capacitor start a toy car?

Hi, I am trying to build a solar powered toy car. And no its not for my son, its for my own curiosity. The problem I am having is that...while the solar panel is sufficient to rapidly turn the (4) micromotors 6 inches away from a lightbulb it isn't sufficient to even turn the wheels when I put...
28. ### Acellerating car vs constant speed car

Hi, I've been dsicussing this with som friends, and would be thankful if someone took the time to explain it to me :) The scenario: Car A travels at constant velocity (80km/h) along the road and hits a brick wall. Car B acellerates upward towards 100km/h, and at excactly the moment it passes...
29. ### Automotive Propeller powered car questions

I'm trying to build a propeller powered car. Right now I'm trying to find ways to make if faster because I'm limited to a 6 volt battery pack. I was wondering if I used a nozzle shaped design like they do for rockets if it will make it faster or slow it down. The propeller is 6 inches and I was...
30. ### Automotive Single actuator Wiper design to wipe a surface area

I'm given this problem to solve with the assumption as stated above. The answers need not be logical as long as the linkage mechanism can be simulated. I've attempted the question using Mercedes Mono Wiper mechanism but only manage to cover 41% given the width of the wiper. May I ask if there...
31. ### Automotive Formula 1 Traction Control tuning

Hello, I'm a mechanical engineering student and I'm working in traction control for Formula 1 cars. The traction control in the cars is simple, too simple: an engine cut is done when the engine is at a certain RPM and slip value. A matrix of four values of RPM and slip has to be provided to...
32. ### Automotive Vehicle dynamics -- Accelerating FBD

Im starting to learn about vehicle dynamics by watching video lectures here , and also reading the books by Gillepsie and Jazar. I´ve got a fundamental question about the FBD of the vehicle. According to Gillepsie :http://imgur.com/a/lGXxw http://imgur.com/a/lGXxw The vehicle is...
33. ### Car's weight shift with torque & angular momentum

I am having trouble visualizing which two tires of a car will be pushed down based on the angular momentum and torque of that car. Let's say if its angular momentum is point OUT while its torque is pointing UP in relations to the picture below. My guess is it's the two right wheels of the...
34. ### What does physics say about Car collision damages?

Thanks for looking into my thread. I find various threads suggest to use Kinetic energy/conservation of momentum to explain car collision. Moving car generate/carry more energy compared to stopped one. I find when a car (car1) (moves with 10-15 miles/hr) rear-ends stopped vehicle (car 2), the...
35. ### Automotive Crash Test Software

For my senior project i plan on litening a vw rabbit car. 1981. Any software that i could uuse to model the care and provide great data on how i could improve the safety after i cut it up to lighten it? Thinking adding roll bars or something.
36. ### How do forces of the tires contribute to car rollovers?

I'm trying to understand the physics of car rollovers and perhaps what can prevent them in terms of the forces that are involved. According to various diagrams I've seen, there is friction applied by the tires (with some diagrams showing a set of forces acting only on a single tire which...
37. ### Automotive How do Center differentials work

Greetings all, In my quest to imagine the ultimate sportscar, I began to wonder about the following: Certain cars are All Wheel Driven (AWD) and they do so via a Center differential delivering power to both axles. Amongst those cars, some have fixed Torque Bias/Split Ratio, which doesn't alter...
38. ### Vehicle turning radius and path projection

Hi everyone, i hope this is the right place to post this. Anyway, i'm creating a game, and i'm trying to calculate and project future car movement path based on steering angle of the wheels. By using equation: r = wheelbase / sin(steeringAngle) I'm able to calculate turning radius. But the...
39. ### Calculating the force in suspension as a car hits the brakes

Hello, Firstly thank you for reading my post. This is an interesting question I was wondering if anyone here could teach me how to work out. Say if you had a large go-kart (FSAE/Formula Student if anyone knows of that) and you were driving at 120kph and hit the brakes and stopped in 3 seconds...
40. ### Car on road with "infinite" friction

I have been wondering this for a while. I know that tires using static friction due to reasons that I forget and therefor maintain good traction with asphalt. A few years ago family member said that if there was too much friction on a road then a car wouldn't move, but I argued that the car...
41. ### Inertia/ Unbalanced Forces

Homework Statement This is not a specific problem, I was just wondering, what unbalanced force acts on your body when you are in a car travelling at a constant velocity and the car comes to a sudden stop? This has to do with Newton's First Law, but I'm unsure of what force applied to your body...
42. ### Is a car's top speed the same on a wet road?

I'm a games programmer who is writing a simple car physics simulation, and I've had a disagreement with the designer about a car's behaviour - specifically, its top speed - in different conditions. Imagine a car accelerating from a standing start to top speed along a perfectly straight, flat...
43. ### Automotive Selecting electric motors once power requirements are calculated

So for a school project I gotta design an electric car that can meet minimum range and top speed requirements for how heavy it is. I have calculated the amount of power needed(kW) for its heaviest load situation to reach the min speed and range, along with the necessary energy(kWh) required for...
44. ### At what angle should the bomb be released?

Homework Statement There is a plane flying at 200 km/h and wants to drop a bomb on a car traveling 130 km/h which is 78.0m below the plane. at what angle should the bomb be released? the answer is 45 degrees. Homework Equations sine law: SinA/a= SinB/b cosine law: a^2=b^2+c^2+bcCosA v=d/t...
45. ### What is the acceleration of a car at constant speed?

If a car is travelling at a constant speed of say, 60MPH, is the acceleration of the car 0, or is it equal to the drag and rolling resistance it's facing?
46. ### Automotive Could cars have a better fuel economy at low speeds?

The part that I roughly understand: 1) Drag equation, drag increases by square of velocity, thus if it was only factor to be taken in to account then the lower speed the better. 2) In case of cargo ships there is a policy of decreasing speed to reduce fuel usage, called "slow steaming". It...
47. ### Automotive How does the throttle affect the RPM of an engine?

Hello, I'm working on a car simulation and I'm attempting to implement a manual transmission simulation into the game. My question is, how do you find the rate of change of the engine's RPM when the gas pedal is pressed in the car?
48. ### Car Alternator voltage is too high (16V+) Can it be reduced?

My car alternator runs at 16 to 16.5 volts when I hit the gas, and 15v idling. This is scaring me and a new one is too expensive. It could be my computer or pulleys in the wrong too so I can't risk buying a new one and still having the problem. It turns off my speaker amplifier as soon as I hit...
49. ### Automotive Car that can you drive forever

Hello , this is my first post. I just had this crazy idea if you can make a car that you can drive forever. I just want to check if this is possible. I know that the "motor powers the generator and generator powers the motor" thing doesn't work. Cause it isn't 100% efficient and bla bla bla...
50. ### Vehicle Acceleration Curve

I am programming a game in which there are no outside forces acting on the car aside from the engine. I will not be having gears, so that is not a factor. I just want to know if there is an equation I can use to calculate the car's speed at any given time. The car will start off accelerating...