1. Not finding help here? Sign up for a free 30min 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!

Calculate resultants of two forces

  1. Jan 27, 2013 #1
    1. The problem statement, all variables and given/known data

    Where does the resultant of the two forces act?

    http://i.imgur.com/CBO8fi2.jpg

    2. Relevant equations

    None really. Basic algebra for calculating resultants.

    3. The attempt at a solution

    First off, I have tried to calculate the x and y components of the resultant, call it R. Here I think that R_{x}=0 (both forces are vertical) and R_{y}=-20 (net force in the y-direction). So the resultant is:

    R=R_{x}+R_(y} = 0x-20y with magnitude of 20N. However, I am unable to understand how the lengths will help me.
     
    Last edited: Jan 27, 2013
  2. jcsd
  3. Jan 27, 2013 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    The question wants you to replace the two forces at different distances with one force that has the same effect. So - what is the effect of each force as drawn? (Hint: what is special about point A?)
     
  4. Jan 27, 2013 #3
    That is what I have tried to do actually. I have replaced them with one downward force with magnitude 20N. But I don't know where it is located.

    What is special about point A? Well, not sure. There must be a force to compensate the downward force but that is done by the beam(object).
     
  5. Jan 27, 2013 #4

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    20N is what you'd get if the forces acted along the same line.
    Do they?

    Won't each of the two forces create a moment about point A?
     
  6. Jan 27, 2013 #5
    Yes, I suppose. I will have to think a little bit about this one before I answer. Not sure about the theory yet.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Calculate resultants of two forces
Loading...