1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: How to find he coefficient of kinetic friction?

  1. Oct 12, 2011 #1
    A flight attendant pulls her 70.0 N flight bag a distance of 269 m along a level airport floor at a constant speed. The force she exerts is 32.0 N at an angle of 52.0° above the horizontal.

    (a) Find the work she does on the flight bag.

    (b) Find the work done by the force of friction on the flight bag.
    _-5299_ J
    (c) Find the coefficient of kinetic friction between the flight bag and the floor.

    i found part A, by 32.0 x 269 x cos(52.0) = 5299J

    but i dont understand how to get part c

    i keep doing 32Cos(52)=70-32sin(52)k and i get .1357, dont get what im doing wrong HELP!??
  2. jcsd
  3. Oct 12, 2011 #2


    User Avatar
    Gold Member

    What is the matter with the value .1357?
  4. Oct 14, 2011 #3
    the answer is .4397
  5. Oct 15, 2011 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    What is the normal force the floor exerts on the flight bag?

    Draw a Free Body Diagram.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook