What is Car: Definition and 998 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. Hak

    I Paradox of the car and the driver in SR

    I would like to propose a relativistic problem that I cannot understand. A car of rest length L travels at close to the speed of light towards a garage, of length L, which also has an opening at the bottom. For a person next to the garage door, the car has a length less than L, due to the...
  2. A

    Advice needed for producing a water powered car model project

    TL;DR Summary: We were tasked to create a water powered car for a project for engineering design and the main specifications is as follows, it must hold 0.7L a min of water. For the first run it must move as far as possible with 0.5L of water and then on the second run it must be able to move...
  3. Eclair_de_XII

    I need a second opinion on a sanitation fixation I've been having (TW)

    On Saturday, I had to transport a used toilet brush in my car. Beforehand, I had washed the handle roughly, and ran the bristles under hot water. I am afraid that I had not washed it thoroughly enough. I had had to pack it into a small box, which I placed on the floor of the backseat of my car...
  4. L

    I Car, wheels and Lorentz contraction of the road: Is this a Paradox?

    A car travels at low speed on a road from start to finish, and counts the number of turns of the wheel, which gives it a road length of N.2πR, where R is the radius of the wheel. Then he does the race again at relativistic speed. He sees the road with a Lorentz contraction. However, he has to...
  5. alex33

    Wheelie of a car coming out of a ditch: what is the correct model?

    I ask for help in interpreting this question. Thank you !
  6. Grizzly_1

    The advisory speed for a car on a sloped bend

    Hello all, I am sadly stuck on the last part of a circular motion question sheet I was given for homework. I have a mark-scheme with me, but it has actually given me more questions than answers. I have attached my working, and how I arrived at my answer, and the differences it has with the...
  7. kyphysics

    I Car Accident Physics - Are Wheels/Tires Good or Bad Energy Absorbers?

    Here's an applied everyday life physics question based on a MVA (motor-vehicle accident) I was involved in a few weeks ago. I was driving straight when a women hit me from the driver side (said she didn't see me due to being in her blind spot - her claim, not mine, as I don't know if I was or...
  8. M

    Racing car coolant formula ideas

    Hey guys! So, I’m working on an engine coolant for track motor sports that can’t contain any glycols. I think a simple “water wetter” will work. A surfactant such as Tydol X-100 come to mind along with an anti foaming agent and aluminum corrosion inhibitor. I know there are commercial...
  9. DagmaarUlereich

    Outlet adapter to mimic a car battery to power 12V devices

    Sorry if this is a very simple question but i have been googling and looking around for a straight anwser but can seem to find a solid answere or draw a solid conclusion from information I've reached. So I have a rgb led light for a car, the box says input 12vDC. if I wanted to set these up...
  10. B

    I need help with a car anti-theft device circuit schematic

    I'm working on a school project and I have to find and/or make a circuit schematic to a car anti-theft system that will disconnect the car battery shortly after the car alarm goes off. I am new to the electronic engineering field but I can differentiate a few different components on a schematic...
  11. G

    I Realistic steering wheel angle when car follows points along a path

    Good morning , I managed to simplify the physics of my car with only the centrifugal and traction forces. If I'm in control of it, the realism is acceptable for a city builder. On the other hand, I encounter a problem when the car follows an array of points. The path of the car on my graph...
  12. Bike Mi Vie

    B Negative pressure in a car to power it

    My father has an idea is powering vehicle using negative pressure. I'm trying to explain to him that I don't think that can work. He is saying that imagine you're in space and you try create negative pressure by keep on removing and the only thing that's preventing the collapse of the material...
  13. J

    B Car Crash Physics: Deceleration Calculations

    Hi, I was watching a documentary on car crashes and how designs are continually being optimised to keep passengers safe. They were saying how many ‘g’s’ certain crashes were based on crumple zones, seatbelt stretch etc. I was interested to do some number crunching to see how big the...
  14. Beginner1

    Building a Flying Car from Frisbie Aerodynamic Principles

    MENTOR Note: Post moved from General Discussion to Aerospace Engineering How did you find PF?: I found PF because of a late night idea I had when I was bored, but I have no idea how to do it so I was looking up information when I came across this app. I'm sure most of you guys on here know...
  15. J

    Ideal car rear roofline angle and shape for low drag?

    What is ideal rear roofline(rear window and trunk) angle and shape(straight line, curve ..etc) for lower drag? Keep in mind if you increase angle, you reduce butt area / wake, but induce low pressure at rear window/trunk , if you decrease angle you increase butt/wake but increase pressure at...
  16. J

    I Car low average speed vs aero drag relation

    I drive car only at country roads allways at speeds 100-120km/h, no city and no idle time-heating engine etc. Why computer allways show very low average speed , 40-48km/h?I allways have feeling that this speed is too low because I allways drive way faster then this. Indeed all my friends have...
  17. J

    I Car weight is drag on uphill but thrust on downhill? (effects on fuel consumption)

    When car drive uphill, gravity/weight has drag component, that is reason why you must add more throttle compare to ligther car at same constant speed uphill. So logicaly car increase fuel consumption. But if you drive downhill, gravity/weight has thrust component, so your top speed("terminal...
  18. kyphysics

    Auto/Motor Car Maintenance: Costs, Recommendations, and Debates

    A thread where we chat about car maintenance. What maintenance are you doing lately? What cost did you pay? What are things you've been recommended by your servicer that you're undecided on doing? Here is one for me: "engine system cleaning" ($200) The tech said it's recommended...
  19. S

    Distance travelled by a car considering only air friction?

    TL;DR Summary: Distance traveled by a car considering only air friction? How much distance would a 3-ton car travel if its initial speed was 17 km/h and we only take into account air's friction? (Assume that the car has an airfoil-like shape, so that the resistance against the air is very low)...
  20. M

    How to find velocity of gas pump flowing into car tank

    The general balance equation is as follow: d[m{u+gz+v2/2)sys=(u+gz+v2/2)dmin-(u+gz+v2/2)dmout +dq+dw. I understand that I would take in consideration the cross sectional area as well as the mass flow rate. However I can't figure out what else to consider as if atm pressure should be considered...
  21. A

    B Doppler effect on electromagnetic waves in a car

    Is the doppler effect on electromagnetic waves receive by cell phone in fast car and so somebody talk with cell phone in fast car view this effect
  22. J

    I Car drag coefficent vs fuel consumption link

    Car has drag coeffecient of 0.35 and drink 5L/100km, if car Cd is reduced to 0.20 and everthying else stay the same(frontal area,power,weight etc),how much will car drink? Is it possible to calcualte this or we need something more? I am interested if exist direct link/formula between Cd and...
  23. S

    EMF produced by generator of a car

    First I assumed the question asks about max e.m.f so I just used ratio: output voltage = (2500 / 1100) x 12.7 = 28.9 V, but the answer is wrong. Then I tried to use the ratio of the whole formula: $$\frac{\varepsilon_{1}}{\varepsilon_{2}}=\frac{NBA \omega_{1} \sin(\omega_{1}t)}{NBA \omega_{2}...
  24. C

    I Steering a Car: Investigating the Forces of Rotation

    In a car we turn the wheels to steer. The wheels however are spinning about their axis of rotation when the car is in motion. Does the revolving motion of the wheels cause a force that opposes trying to rotate the wheels around the other axis to steer? How much opposition is created? Here's...
  25. S

    Semiconductor technology progress for car controllers (ABS, ESP, ....)?

    Hi! How does progress in semiconductor transistors such as Si to SiC or GaN, MOSFET to FinFET, 10nm to 2nm, etc. improves the performance of a controller such as the ABS, ESP, ESC, ... of a car? And how much is the impact of transistor technology progress on such a controller (compared to...
  26. S

    Thermal energy dissipated from the brakes in a car

    My sign doesn't check out and I don't get why that'd be the case. Forces that act --> ##F_{fr} and F_g## derivation: ##\Delta K = W_{NC} + W_C (1)## ##\Delta K + \Delta U = W_{NC}## ##\frac 12 mv_2^2 - \frac 12 mv_1^2 + mgy_2 - mgy_1 = W_{NC}## NOTE: ##y_2## assumed to be datum line so ##y_2 ==...
  27. dlgoff

    New Car Battery Plant Construction in the Midwest

    Panasonic is going to build an electric car battery factory plant in DeSoto, KS. Will hire 4000 jobs at the plant and another 4000 jobs throughout the state. IIRC, the factory will cost 4 billion dollars to build. edit: corrected spelling of DeSoto
  28. James Brown

    B How come friction can make a car turn?

    How is it possible that friction makes car turn? From what I know, frictional force is acting along to the direction of the wheel turns. When the car turns, the direction of the frictional force now act opposite to the direction of the wheel turns! I'm sure if you rotate the steering wheel to...
  29. shuumi

    Stuck in a question from exam -- Car decelerating to avoid hitting an obstacle

    i tried but i wasn't able, maybe i choose the wrong formulas in the wrong time.
  30. S

    Why would disconnecting the positive cable first on car battery cause sparks?

    When I was 18 years old, I worked at an automobile repair shop doing oil changes and other light mechanical work. The automobile repair shop hired me for this work to free up their real auto mechanics to do more advanced automobile repair work. One time I was assigned the task of replacing a...
  31. Grez

    Automotive How to calculate max car mass and tow capacity from motor specs?

    Hi I am trying to do an artisanal EV car and I would like to know how do I choose the right motor. I already have one in mind but I don't know how to calculate the max mass that it can move. (see attached pdf) Gear Ratio : 2.39 Diff Ratio : 4.88 Wheel Diameter: 26in I would like to know the...
  32. V

    Forces when car wheels "lay rubber"

    Suppose the car is moving to the right, so if the wheels roll without slipping, they are rolling clockwise. To get the wheel to slip, a counterclockwise torque would need to be applied to cause the wheel to have some angular acceleration. If the wheel was slipping, then the bottom of the wheel...
  33. J

    I Direction of friction of each wheel and total moment when a car turns

    Static friction is known to provide centripetal force when a car turns. Assuming uniform circular motion, my questions are 1. Is the static friction of each wheel points toward the center of turning circle or it's the combined forces of all four wheels that has to point toward the center of...
  34. T

    Ways to improve the washing of car rims

    Hi have to develop a mechanism which can wash car´s rims in a more effective way than car wash stations do, mainly by focusing on the geometry of the brushes and their motion... (circular motion is apparently not enough and that's why car´s rims don't get properly cleaned after a wash... Any...
  35. karush

    MHB 51 How far will the car travel in 10 sec

    How far will the car travel in $10$ seconds" \begin{align*}\displaystyle \Delta t&=10,\quad a=2,\quad d_i=0,,\quad v_i=0\\ d_f&=d_i+v_i\Delta t+\frac{1}{2} a \Delta t^2=0+0\cdot 10+\frac{1}{2} \cdot 2\cdot 10^2=100 \, m \end{align*} or $\displaystyle v=\int{...
  36. wheelman

    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...
  37. K

    Calculating the force of an average car

    Hi everyone, I'm interested to know how much kilograms force an average car can produce. I made the following calculations to answer my question but I'm not sure if I'm right or wrong! Imagine we have a 1.8L engine that can produce a max torque of 155 nm @ 4250 RPM. 1st gear ratio = 3.455...
  38. phinds

    Impossible 180 degree car turn

  39. moriah

    Regular Grade Gas and its Effects on Car Engines

    Is regular grade gas detrimental to a car’s engine?
  40. S

    Verification of a problem -> force needed for car stopping in 1.8cm

    hello guys can someone verify my solution (in the picture) whether the solution is correct or I guess the steps followed would be enough. There is no solution in the book for this one but wanted to be sure. Thanks in advance
  41. rudransh verma

    A truck and a car coming to a stop

    If ##F## is constant, then mass is inversely proportional to ##dv/dt##. But ##dv## is constant too. So mass is proportional to ##dt##. More massive the body more time it will take to stop covering more distance. So car will cover less distance. Is my logic right ?
  42. rudransh verma

    Sphere and accelerating car

    If I draw the fbd then some force will accelerate the car in horizontal direction which I think does not effect the string in vertical direction. So same tension regardless of acceleration. But we know it will increase. So what will be the correct physics behind it?
  43. moriah

    Effects of Collision on Car Body/Frame

    Do medium to high level car collisions create cracks/fissures in the frame and body of the car?
  44. B

    B Forces on a passenger in a car?

    What would the forces acting only on a passenger in a car going at constant speed on a level surface be? Of course, there would be weight and the reactive force acting on any passenger, but is there a horizontal net force? Or are there just the forces acting on the car and there are no...
  45. J

    Car lift using suspensions as lift points

    Some car lift service centers want to lift up the car by using the suspensions. I always told them to lift by the pinch weld jack points near the tires. Are there some suspension system where the service center can lift the entire car by via the suspensions. And are there some cars which they can't?
  46. chwala

    Calculate the speed of car for maximum economy

    This is the problem, This is the textbook solution ; i think the textbook solution is not correct! My thought, ##S_{max}## will be given by $$\frac {dy}{dS}=0$$ $$\frac {dy}{dS}=\frac {-1}{400}S+\frac {1}{5}=0$$ $$S=80$$ It is maximum economy because ##y{''}<0##, i.e by use of the second...
  47. J

    Plugging a hole in a car tire

    This is one method to fix a tire with hole. I'd like to understand what happens mechanically to the tire belts and plies when plug method was used to fix the hole. This is part of a tire. Now imagine you push a tool into the hole (like in the video), would the belt and ply simply have...
  48. Father_Ing

    Car that undergoes non-uniform circular motion

    In the solution manual, it says that: the resultant of friction force is ##<= kmg##, hence $$m\sqrt{\omega_t^2 + (\frac {v^2} {R})^2} <= kmg$$ and from this equation, we will get $$v^2 <= R \sqrt{(kg)^2 -\omega_t^2}$$ which will make ##v_{max}^2= R \sqrt{(kg)^2 -\omega_t^2}## Finally, they...
  49. chwala

    At what time will bike and car be side by side again - Mechanics

    Find the question below; For part (a), i used the graph to find ##t=22## For part (b), i considered the points; ##(8,20)##, ##(13.333,20)## and ##(0,0)## it follows that, Area=##\sqrt {25.454(25.454-21.54)(25.454-24.036)(25.454-5.333)}## ##\sqrt {2842.58}##=##53.31## There may...