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: Tension Problem

  1. Oct 14, 2008 #1
    1. The problem statement, all variables and given/known data
    A block with eight of 455 N is being pulled at constant velocity by a force directed at 30 degrees above the horizontal. The friction force on the crate is 1163 N. What is the magnitude of the pulling force?

    2. Relevant equations
    Ft= kx
    Fnet= ma


    3. The attempt at a solution
    I tried to use the component method to find the force in the x direction and then so that I could find the pulling force but it doesn't work!!!
     
  2. jcsd
  3. Oct 14, 2008 #2

    cristo

    User Avatar
    Staff Emeritus
    Science Advisor

    What, specifically, did you try?
     
  4. Oct 14, 2008 #3
    I tried using 445 N cos 30 degree to find the vector on the x direction, that's how I was taught!!
     
  5. Oct 14, 2008 #4

    cristo

    User Avatar
    Staff Emeritus
    Science Advisor

    445 N is the weight of the block, which acts vertically downwards, so I'm not sure why you're resolving that into the x direction.

    You have several pieces of information: the block has a weight of 445N; it is travelling at constant velocity; the pulling force is 30 degrees above the horizontal; the friction acting on the box is 1163N.

    So, first things first, I would draw a free body diagram including all the forces. Can you do this?
     
  6. Oct 14, 2008 #5
    sure, I do

    and I did draw it

    so to the left is the friction force

    and 30 degrees above the horizontal is the acting force

    the gravity is 9.81 and from there I can find the mass of the object

    and I have to find the pulling force

    thank you very much for you help

    I will try my best and see what I get
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook