Car Definition and 999 Threads

  1. M

    MHB Testing the Assumption of Car Model's km/L Performance

    Hey! :giggle: Some people assume that a specific car model does at least $\mu_0=120$ km with $1$ Lt benzin. $10$ independent tests give the following results: $$104, \ 96, \ 80, \ 100, \ 108, \ 100, \ 112, \ 120, \ 130, \ 132$$ (a) Give the Null Hypothesis $H_0$ and the alternative...
  2. yucheng

    What's the error in my solution (Freight car and hopper)

    Textbook solution: ##v## is the instantaneous velocity, $$P(t)=(M+b t) v$$ Then $$impulse = \Delta P = (M+b t) v = \int^{t}_{0} F dt'$$ Thus $$v=\frac{F t}{(M + bt)}$$ What I did instead was: Let ##M## be the instantaneous mass, and ##M_0## be the initial mass, then $$M=M_{0} + b t$$...
  3. Frabjous

    Frost preferentially forms on non-vertical car windows?

    Going out to my car this morning, I noticed that frost preferentially formed on non-vertical windows. I can come up with three explanations 1) non-vertical windows are dirtier, providing more nucleation points 2) horizontal vs vertical boundary layer effect 3) gravity driven vertical diffusion...
  4. lion1014

    Grade 12 Kinematics -- Will the car stop before the cliff?

    t= v/a =25.8 m/s / -2.5 m/s^2 =10.1 s therefore, d= vi * t + 1/2at^2 = (25.8)(10.1) +1/2(-2.55)(10.1)^2 =131 m I got the first one right I think, but I don't know how to do b
  5. chucho11028

    Motion in one dimension -- Experiments with a Hot Wheels car rolling down a ramp

    Hello This is not a homework, this is my own experiment to understand how the motion works. Please, follow my question here below: I have a hot wheels race with a slope with 10 degrees where I use a small car which departs from the top to the bottom. I have taken 5 times the time to get an...
  6. F

    Danger of spending time inside a running, not moving car

    Hello Forum, I am not sure this question really belongs here but I was not sure where else to post...it is about science and health after all. I started thinking about this question seeing so many people have sadly become homeless and living in their cars because of the pandemic and job crisis...
  7. stphnls

    Crane Lifting a Car -- Find the Work Done

    W= Fd W= 3NX1.20m W= 3.6 J is the work done by the crane W=Fd W=0.6Nx1.20m W=0.72 J is the work done by the car I have no idea how to solve the c, I am thinking at first that the work done by the crane and the car are zero because cos 90 is zero and there are perpendicular to each other. I...
  8. NickTheFill

    Modelling the tyre as a spring in a quarter car model

    Hi everyone I've just completed a mechanical engineering degree, and one aspect of the classic 2DoF quarter car model that still bugs me is the representation of the tyre as a linear spring attached to the ground. Does anyone have any experience of modelling the system with the tyre spring...
  9. kyphysics

    COVID Could COVID Travel from Car Trunk into Main Car Area from Drive-Up?

    I do curbside/drive-up pick-up service from various businesses. I order on their app. They pack it and when I arrive to the store, they put it in my trunk. No contact. I never have to roll down my window even. I let the groceries (non-refrigerated) or retail goods sit in the trunk for a...
  10. J

    Electrical Converting Old Filament Car Lamps to LED: Considerations for Focusing Light

    I want to change the the old round 5000 series filament bulbs to led. I attached a picture of some I found on Ebay. I see some led bulbs seem to mention some thing about fan. One way would be cut hole in old glass bulb and glue led in with silicon. Could use glass jar and drill hole in cover...
  11. anorlunda

    Automation Ethics: Should your car serve you or serve society?

    Tesla’s Autopilot a ‘distant second’ to GM’s Super Cruise system in Consumer Reports testing I think this is very interesting because of Consumer Report's reason for their evaluation. The GM autopilot aggressively monitors the driver to make sure he/she is alert and paying attention. The GM...
  12. jack action

    Discover the World's Nicest Car Horn That Will Change Your Driving Experience!

    I usually find new ideas being only useless gadgets. But this, I could go for it, so I'm promoting it. source: https://www.facebook.com/MarkRoberYouTube/videos/1254798328186209/
  13. aatari

    Angular Distance driven by a car going around a roundabout

    Can someone look at my solution to see if it is correct.
  14. jaumzaum

    Question about car braking and tire friction

    I'm a little confused about this question because I think the braking deceleration probably takes into account the braking system of the vehicle as well as the power of the motor. I don't understand how a car could actually brake without the "friction between the mechanical components of the...
  15. shk

    Force and motion -- A water drop on the windscreen of a car

    Hi Please help me with part C. I have answered the question and have attached it for you to see.
  16. W

    Motion equation problem -- Car accelerating with a constant power engine

    So I tried to solve this in two methods, but I keep getting different results, and I don't know why.
  17. B

    Homework: Calculate the work done to accelrate a car

    Homework Equations Conservation of energy. Kinetic energy=(1/2)mv^2 The Attempt at a solution m=1.5*10^3kg, final velocity=25m/s, initial velocity= 11m/s, distance=0.20 and work done=? What do I do next.
  18. J

    Frame of reference question: Car traveling at the equator

    Earth rotate from west to east with 460m/s at equator. Car travel at equator from east to west at speed 460m/s. 1- What is car speed from inertial ref.frame? zero?How is zero if car travel in curved line? 2-What is car speed from rotational frame ? 3-How much is car weight,compare to car...
  19. G

    Car Radiator as Air-to-Water Heat Exchanger

    I am looking for a passive way to convert a supply of hot air into warm pool water. My pool can be in the low 70s without heat. Looking to get a 10 degree lift in pool temp. Pool is in-ground and relatively small at 8,500 gal. Water flow rate through the radiators can be regulated by valves...
  20. N

    Kinematics question: Stunt driver jumping his car from ramp to ramp

    Do i use the equation above mentioned to solve it? If i do, am i correct to say that Vx = 90/3.6 cos 30 and Vy = 90/3.6 sin30?
  21. nirgro

    Help please with a physics bet (2 cars colliding vs. 1 car hitting a wall)

    so the question is this. 2 cars with the same mass hits each other at the speed of 30 miles. at which speed a car needs to hit a wall in order to get set same impect? i don't care what Will hurt the driver more. thanks!
  22. AN630078

    How Do You Solve Simultaneous Equations for Time and Distance in a Car Journey?

    Equation 1: Where t1=time spent on motorway Where t2=time spent on country roads t1+t2=4 Equation 2: Using distance = speed * time 200 = 70*t1+40*t2 Rearrange equation 1 in terms of t1; t1=4-t2 Substitute the rearranged form of equation 1 into equation 2: 200=70(4-t2)+40t2 200=280-70t2+40t2...
  23. AN630078

    Circular Motion of a Cyclist and a Car going around a bend in the road

    Question 1: So we are given three variables; Mass=90kg Angle to the vertical = 20 degrees Speed = 10 ms^-1 There is not enough information to rearrange the formulas for centripetal force or acceleration in terms of r to find the radius. However, I have a attached a free body diagram of a...
  24. badluckmath

    A simple pendulum is suspended from the ceiling of an accelerating car

    Here is an image of the problem: The problem consist in finding the moviment equation for the pendulum using Lagrangian and Hamiltonian equations. I managed to get the equations , which are shown insed the blue box: Using the hamilton equations, i finally got that the equilibrium angle...
  25. badluckmath

    A simple pendulum is suspended from the ceiling of an accelerating car

    Here is an image of the problem: The problem consist in finding the moviment equation for the pendulum using Lagrangian and Hamiltonian equations. I managed to get the equations , which are shown insed the blue box: Using the hamilton equations, i finally got that the equilibrium angle...
  26. Stephen Bulking

    What happens when a car turns?

    A car moving at constant speed is in uniform circular motion, thus having centripetal acceleration of ##a=\frac{v^2}{R}##. The force associated with this acceleration is known to be friction. But friction, in nature, appears as an opposition to the relative motion between two surfaces whether it...
  27. J

    Car in corner -- relative airflow

    http://mccabism.blogspot.com/2017/08/curved-flow-and-arrows-a3.html "The nose skirts on the Lotus 80 and Arrows A3 would have suffered from the fact that a Formula 1 car has to generate its downforce in a state of yaw. Thus, in a cornering condition, a car is subjected to a curved flow-field...
  28. anonymous99999

    When Will the Car Overtake the Truck?

    A truck passes a point A on a straight level road with a constant velocity of 10 m s -1. At the same instant, an automobile starts from rest at point A and travels in the same direction as the truck, with a constant acceleration of 1.6 m s -2. How long a time does the automobile take to pass...
  29. Andrea Vironda

    Automotive Aerodynamic drag on a car and recovering some of that energy using a fan

    I think that driving at 130-140 km/h a car could dissipate 5-10 kW of energy only because of aerodynamic drag. Why cars don't have a fan somewhere to exploit the aerodynamic drag? For example a Pelton turbine
  30. Selfphysicslearner

    Why does a car apply a force to a wall?

    when we have 0 acceleration(constant speed) like a car traveling at a constant speed, ƒnet=ma ƒnet=(mobject+mfriction).(aobject+afriction) let m object be 1500 kg. m friction be 10 kg a object be 0 a friction be 20m/s^2 so when we calculate fnet=-20*1600=-32 000 Newtons. which means wall applies...
  31. F

    Finding Velocity of Car Slowing Down: v_0-c*(t-t_1)^2/2

    At time t=0 , a car moving along the + x -axis passes through x=0 with a constant velocity of magnitude v0 . At some time later, t1 , it starts to slow down. The acceleration of the car as a function of time is given by: a(t)= 0 0≤t≤t1 -c(t−t1) t1<t2 where c is a positive constants in...
  32. RemotePhysics

    Futher Mechanics: Circular Motion of a Car Going Around a Banked Turn

    Below is my working out. If you could have a look at my answers and see if they are correct and then advice me on how to improve my solutions for Parts I and II, and how to answer F and G with the given information. Thanks in advance! Parts aand b are diagrams so please refer to the attached...
  33. G

    To find the relative velocity of the wind as seen from a car

    Could I please ask for any help with the following question: Here's my attempt: (i and j are unit vectors in the directions of east and north respectively) (apologies that LaTeX is simply not working for me, I'll label the angles in each case T and P as shown in my diagram) Let the...
  34. J

    MHB Engineering Mechanics: car speeding up

    A car starting from rest picks up at a uniform rate and passes three electric post in succession. The post are spaced 360 m apart along a straight rod. The car takes 10 seconds to travel from the first post to the 2nd post and tales 6 seconds to go from the 2nd post to the 3rd post. Determine...
  35. D

    Hydraulic Car Ramps...... need to make them go up and down

    I currently jack up the end of the ramps using the channel frame and a 3 1/2 ton jack, because of the height of the channel frame I have to have it sitting quite far back under the car for clearance when the ramp is lowered down to drive off. I have to push the jack a long way under the car to...
  36. R

    Angular Velocity of a Car going around a curve

    θ=90°= π /2 so the instantaneous angular velocity dθ/dt= lim∆ t -> 0 (θ(t + ∆ t)-θ(t))/(∆ t) When I calculate it out it is π /2 radians per second. Is this correct?
  37. I

    Travel time for an accelerating car

    Hi guys, i hope i find the right Sub-Forum. Can you please tell me if i calculated it right. A car speed's up with 5 m/s² to a speed limit of 50Km/h. After it arrived the speedlimit it drives for 30s with the speed of 50km/h. After that it break with a negative acceleration 3.0m/s² to stop...
  38. LCSphysicist

    Man on a railroad car rounding a curve

    "A man of mass M stands on a railroad car which is rounding an unbanked turn of radius R at speed v. His center of mass is height L above the car, and his feet are distance d apart. The man is facing the direction of motion. How much weight is on each of his feet?" I came five equations, and...
  39. aspodkfpo

    Car turning and centripetal force

    1. When a car turns there is a centripetal force towards the centre. This centripetal force is labelled as a static frictional force. I don't understand where this static frictional force arises from. Friction is meant to oppose motion, but I don't see the motion that is parallel to the friction...
  40. MustafaTekinay

    How much force does a moving car exert on to the road?

    I understand that the weight of the car does not change (assuming mass of the car stays the same) because of f=mg. But I am not so sure about of the aerodynamics of the car plays a role. Say, a faster car might have more air under their wheels and might exert less force on to the ground. Maybe a...
  41. M

    Giving a jump start to a car - how does the circuit become complete?

    Car A has a dead battery and car B gives a jump to it. I connect the positive of battery B to the positive of battery A and the negative of battery B to the body of car A. 1. Am I essentially creating a separate circuit by choosing a different ground than that of battery A? How is the current...
  42. Evo

    Actor-comedian Orson Bean, 91, hit and killed by car in LA

    Sad to hear, watched him on tv all of my life. R.I.P. https://www.yahoo.com/entertainment/actor-comedian-orson-bean-91-114135652.html
  43. kuruman

    Work is not done by static friction when accelerating a car

    A recent thread posed the question whether work is done by static friction in the case of an accelerating car. Before I had a chance to reply, the thread was closed on the grounds that the subject was "beaten to death". Undaunted, I am determined to deliver the coup de grâce here with a simple...
  44. Vortex8380

    Mechanics problem — Car moving with constant acceleration

    I tried this but I don't know if it makes sense: Average velocity from A to B = 22/2 = 11m/s Average velocity from B to C = 104/4 = 26m/s (26-11)/6 = 3.75m/s
  45. A

    Is there any work done by static friction when accelerating a car?

    I'm asking for clarification, but it's my understanding, that of the thread below, and my college physics book Paul A tipler, that when walking or driving a car, the force of friction from the ground does no work. This makes sense in a car becuase the engine/fuel makes the power, driving the...
  46. J

    Energy in chemical rocket fuels compared to car fuels

    I am no expert, so forgive me if I sound rather ignorant, but I'm curious about this: are typical automobile fuels like gasoline, diesel and ethanol more energetic than, specifically, *chemical* rocket fuels [like perhaps the types used in missiles, space-bound rockets and such] if measured by...
  47. CheatCod

    Help with a grade 12 physics project — small recoil powered car

    Summary:: We have to make a car which -Has to have a trigger mechanism -after 5s the car launches a projectile backwards to push the car forwards at least 6m -NO ELECTRICITY ALLOWED, no motor, timer, etc -weight limit of 1kg Here it goes, we have to create a car powered solely by gravitational...
  48. Roberta314

    Physics Project Ideas for this Competition please (self-propelled car)

    Hey guys I'm currently working on a school physics project and I need some ideas for it. So basically the goal of the project is to create a vehicle that has to propel itself forward by firing a projectile backwards. The vehicle will be judged based on a scoring system that includes 3 criteria...
Back
Top