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!

Constant speed and friction (please help)

  1. Jul 4, 2007 #1
    Okay, here's the question:

    A box full of physics books (31 kg) is pushed across the floor at a constant speed by a force of F = 85 N at an angle theta = -40 degrees. Determine the coefficient of kinetic friction between the box and floor.

    My question is (for later calculation) if the box is moving at constant speed, does the F = 85N really matter?
  2. jcsd
  3. Jul 4, 2007 #2


    User Avatar

    Staff: Mentor

    Absolutely - that force (the horizontal component....) is what opposes the friction to keep the speed constant.
  4. Jul 5, 2007 #3

    Doc Al

    User Avatar

    Staff: Mentor

    That force also affects the normal force, which you'll need to figure out to calculate the coefficient of kinetic friction.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Constant speed and friction (please help)
  1. Friction help, please (Replies: 15)