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!

Resultant force from three forces.

  1. Aug 28, 2012 #1
    1. The problem statement, all variables and given/known data
    http://session.masteringengineering.com/problemAsset/1127110/6/Probs.2-39_40.jpg
    I will refer to this picture for the problem.
    I have to find the resultant of the three force vectors. I know all except F1 and theta. I am given it for this problem to find the resultant. F1=510N and theta=20 degrees.


    2. Relevant equations
    Each theta is the degrees from positive x axis.
    Fx1cos(theta1)+Fx2cos(theta2)+Fx3cos(theta3)=x
    Fy1sin(theta1)+Fy2sin(theta2)+Fy3sin(theta3)=y
    sqrt(x^2+y^2)=answer


    3. The attempt at a solution
    510cos(70)+600cos(150)+400cos(30)=1.22
    510sin(70)+600sin(150)+400sin(30)=979.24
    sqrt(1.22^2+979.24^2)=979.24
     
  2. jcsd
  3. Aug 28, 2012 #2

    Redbelly98

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Welcome to Physics Forums.

    For the 600 N force, the angle is not 150°. Look carefully at the figure again.
     
  4. Aug 28, 2012 #3
    The angle for 600N should be 4/5 for the x direction and 3/5 for the y direction. Now how do I find the angle? Thats the next part.

    Edit: Nevermind. I got it. Thank you
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook