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!

Quick homework question

  1. Apr 2, 2009 #1
    1. The problem statement, all variables and given/known data

    A 100kg block is pulled at a constant speed of 5.0 m/s across a horizontal floor by an applied force off 122N directed 37 degrees above the horizontal. What is the rate at which the force does work on the block?

    2. Relevant equations

    I know here we will use the instantaneous power formula P=dW/dt or P=Fvcos

    3. The attempt at a solution

    well i drew the FBD and started plugging in numbers in my formula, its just im not sure where the Mass falls into place here I know the answer is 4.9x10[tex]^{}2[/tex] watts but not sure where to go from here thanks
     
  2. jcsd
  3. Apr 2, 2009 #2

    rl.bhat

    User Avatar
    Homework Helper

    In this problem mass is not needed.
     
  4. Apr 2, 2009 #3
    well my answer just doesnt match up with the answer my teacher gave us and i dont know why.... i did 122*5.7sin(37) and came up with 418.5W or 4.2X10^2 W
     
  5. Apr 2, 2009 #4

    rl.bhat

    User Avatar
    Homework Helper

    Your calculation is wrong.
    122*5*cos(37) = ?
     
  6. Apr 2, 2009 #5
    wow! the whole time i was using 5.7m/s instead of 5m/s careless mistake sorry to waste your time
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Quick homework question
  1. Quick homework check ! (Replies: 2)

  2. Quick Homework problem (Replies: 1)

Loading...