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!

I need help in finding correct Coefficient of friction

  1. Oct 2, 2013 #1
    A road vehicle equipped with mechanical wheel brake e.g drum or disc brake ,driving at a speed of 100Km/hr is braked to a stand still with a deceleration of 1G (3.2m/sec^2),How large must be the coefficient if friction between wheel and road at least be to enable that.

    Options:

    1)At least 1.
    2)0.5
    3)2
     
  2. jcsd
  3. Oct 2, 2013 #2

    Mentz114

    User Avatar
    Gold Member

    The force exerted on the truck when the brakes come on ( and lock the wheels) is mg, g=3.2ms-2 and m is the trucks mass.

    Can you calculate the force provided by the friction in terms of the coefficient of friction ?

    (Incidentally the acceleration on the Earth's surface is about 9.7ms-2, not 3.2)
     
    Last edited: Oct 2, 2013
  4. Oct 2, 2013 #3

    berkeman

    User Avatar

    Staff: Mentor

    Check your PMs. You *must* show your efforts before we can provide tutorial help. That is in the PF Rules (see the top of the page under Site Info).
     
  5. Oct 2, 2013 #4

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    I don't know where you got g = 9.7 m/s^2, but there is a different and more precise figure defined:

    http://en.wikipedia.org/wiki/Standard_gravity
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted