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!

Velocity of a car skidding

  1. Jan 29, 2008 #1
    [SOLVED] Velocity of a car skidding

    1. The problem statement, all variables and given/known data
    A 2.20 103 kg car rounds a circular turn of radius 30.0 m. If the road is flat and the coefficient of static friction between the tires and the road is 0.8, how fast can the car go without skidding?



    2. Relevant equations
    Fcentripital=ma
    a=v2/t
    v=2πr/t

    3. The attempt at a solution

    So i used F=ma and substituted F with Coefficient*mass*gravity and for ma i used
    m 2πr/t and solved for t. Then i used the t for the velocity equation and solved it. I got 24.0 m/s but it was wrong. What did i do wrong?
     
  2. jcsd
  3. Jan 29, 2008 #2

    hage567

    User Avatar
    Homework Helper

    I believe you mean this [tex]a = \frac{v^2}{r}[/tex]

    It's r for radius in the denominator, NOT t for time. This is centripetal acceleration here.

    Try to solve it again.
     
  4. Jan 29, 2008 #3
    Thank you soo much for pointing that out but i'm having algebra problems, so if i used
    v2/r but i have no velocity so i use 2πr\t but then i have two divisions, i know this probably is a very stupid question but i'm really bad at math. so how would i put that equation to equal to t. Would it be (coefficient*m*g)/m(2πr2) ??? The answer i got was completely ridiculous so i'm guessing it's wrong.
     
  5. Jan 29, 2008 #4

    hage567

    User Avatar
    Homework Helper

    But you are trying to find velocity, so there is no need to substitute something in for it. You don't need to find the time, either. Just equate the frictional force into the first equation listed in your "relevant equations" and the proper term for "a". Solve for v.
     
  6. Jan 29, 2008 #5
    Thanks. i feel so retarded now that you said that. I got carried away trying to find time that i didn't even realize i was looking for velocity in the first place. So i solved for it and got 15.3 m/s correct?
     
  7. Jan 29, 2008 #6

    hage567

    User Avatar
    Homework Helper

    Looks reasonable to me.
     
  8. Jan 29, 2008 #7
    Thank you!
     
  9. Jan 29, 2008 #8

    hage567

    User Avatar
    Homework Helper

    You're welcome. :smile:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Velocity of a car skidding
  1. Car skidding to a stop (Replies: 8)

Loading...