• Members 457 posts
    June 12, 2023, 5:33 a.m.

    Turning the wheel accelerates the car, but it need not include a change of speed. Right?

  • Members 49 posts
    June 12, 2023, 6:10 a.m.

    Well, technically -- on a race track, at least -- turning the steering wheel slows the car down...

    Aaron

  • Members 457 posts
    June 12, 2023, 6:35 a.m.

    Slowing the car down = negative acceleration. However, in this context, any change in the velocity vector (magnitude or direction) is called acceleration.

  • Members 3952 posts
    June 12, 2023, 6:54 a.m.

    This is getting messy very quickly.

    Since the turning car is moving in a circle are you referring to its centripetal acceleration?

  • Members 457 posts
    June 12, 2023, 9:18 a.m.

    It does not need to be centripetal movement.

    Joke: a physicist failed the driving test because when asked to accelerate he turned the steering wheel.

    Movement is described as a vector. Any change of the vector (length, angle) is considered acceleration.

  • Members 3952 posts
    June 12, 2023, 9:24 a.m.

    Not sure what you mean.

    If a body is moving in a circle then the centripetal acceleration acting on the body is velocity**2/radius, is it not?

    Consequently the centripetal force acting on the body is m x v**2/radius where m = mass of the body.

  • Members 457 posts
    June 12, 2023, 9:29 a.m.

    Yes. That is one example of acceleration when changing direction.

  • June 12, 2023, 10:51 a.m.

    IRL it will always result in a change of speed, because the steering mechanism is never 100% efficient, so some energy is always lost changing the direction of the car, even if it's just making the tyres a bit hotter. That's why after a safety car you'll see racing cars steer left and right, to heat up the tyres.

  • Members 70 posts
    June 12, 2023, 11:08 a.m.

    Here above is one of the reasons why I joined this forum. Thank you Bob, Iliah, Jim, and all the other knowledgeable people who participate here.
    Another very smart person once said: "If you can't explain it simply, you don't understand it well enough."

  • Members 243 posts
    June 12, 2023, 1:02 p.m.

    I was reading this conversation wondering what the heck people were talking about. People may come up with maps and formulas, but anyone who has driven or even watched a race car knows that changing direction scrubs speed. How we can call that acceleration is beyond me.

  • Members 3952 posts
    June 12, 2023, 1:05 p.m.

    Acceleration, positive or negative, is the change in velocity divided by the change in time.

  • Members 457 posts
    June 12, 2023, 1:19 p.m.

    Did you ever have physics in school?

  • Members 138 posts
    June 12, 2023, 1:43 p.m.

    Yeah, probably confusing because the common usage of the word "acceleration" includes a negative corollary, "de-acceleration". Indeed, in standard physics the word acceleration is tagged to any change in velocity, which is defined as the speed and direction of an object . Even turning the steering wheel of a moving car changes velocity, as the direction the car is headed is changed.

  • June 12, 2023, 2:23 p.m.

    It's actually practical verse purely theoretical physics.
    Theoretical physics allows for a 100% efficient steering mechanism whereby steering will not change the speed. In practice the chance of the steering mechanism being 100% efficient is so small to be effectively zero (try steering on an icy road, and you realise that with no friction there is no steering) so steering always changes the speed of a car.

  • Members 40 posts
  • Members 878 posts
    June 12, 2023, 3:01 p.m.

    [deleted]