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!

I have the answer, how did i get it lol

  1. Mar 5, 2010 #1
    1. The problem statement, all variables and given/known data
    Okay, so i am reviewing for an exam next week and ive been looking at my online homework and i ran across this problem and I cannot remember how I solved it:

    You and your friend Peter are putting new shingles on a roof pitched at 23 degrees. You're sitting on the very top of the roof when Peter, who is at the edge of the roof directly below you, 5.4 m away, asks you for the box of nails. Rather than carry the 2.3 kg box of nails down to Peter, you decide to give the box a push and have it slide down to him.
    f the coefficient of kinetic friction between the box and the roof is 0.50, with what speed should you push the box to have it gently come to rest right at the edge of the roof?

    The answer is 2.7 m/s

    I am blanking out and cannot remember how I solved this.



    2. Relevant equations
    I believe:
    Fr=T-fk
    a=Fr/m
    V=Sqrt(2*a*Muk(fric. force))


    3. The attempt at a solution
     
  2. jcsd
  3. Mar 5, 2010 #2

    berkeman

    User Avatar

    Staff: Mentor

    You started by drawing a free body diagram of the box, and applying the kinematic equations of motion. Show us your work as you re-create your original work toward the answer. LOL. :rolleyes:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook