1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Car on wet road

  1. Feb 7, 2006 #1
    A car is traveling at 46.0 mi/h on a horizontal highway.
    If the coefficient of static friction between road and tires on a rainy day is 0.101, what is the minimum distance in which the car will stop?

    Just confused on where to start becuase it seems like I need more info
     
  2. jcsd
  3. Feb 7, 2006 #2
    There is something missing. Don't you have a weight of the car ?

    You should apply :
    [tex]x = v_ot -a \frac{t^2}{2}[/tex]
    [tex]v = v_o -at[/tex]

    Where the v_o is initial velocity and a is the acceleration due to the friction. Beware of the sign !!!

    Solve the second equation for t (the v is zero when the car has stopped) and substitute this t in the first equation to solve it for x.

    marlon
     
  4. Feb 7, 2006 #3
    Thats what I thought but there is no mass given
     
  5. Feb 7, 2006 #4
    ohh yes, just apply newton's second law in the vertical Y-direction :

    [tex]ma_y = 0 = N -mg[/tex]

    normal force N equals N = mg

    and friction force F = 0.101N = 0.101mg

    The associated acceleration is F/m = 0.101g and g=9.81 m/s²

    marlon
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Car on wet road
  1. Car moving down road (Replies: 2)

Loading...