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: Coefficient Static Friction Problem

  1. Oct 23, 2007 #1
    Hey guys, i attempted this question and got an answer but i'm not sure if i did it right, since it seemed too simple too me.

    http://www.physics.ubc.ca/~mattison/Courses/Phys170/p170-ps6.pdf [Broken]

    It is question #4 on the link, and what i did was use kinematics to find acceleration then simply use F=ma to find the Friction force, (Ff) and F=mg to find the upward force (Fn) and then use Mui = Ff/FN

    and got an answer around 0.56.

    I was wondering if this is too simple or if the speed of the truck has anything to do with this calculation, since i did not take that into consideration since both the speed of the crate and truck were 80kph (22.2m/s)
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Oct 23, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Looks like you did it correctly to me. All that matters is the speed of the crate when it hits the ground.
  4. Oct 23, 2007 #3
    Thanks Al.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook