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!

Given the concurrent forces, Determine the resultant

  1. Aug 4, 2015 #1
    1. The problem statement, all variables and given/known data
    F1 = 10N at 37 N of W
    F2 = 15N North
    F3 = 14 N toward the negative z-axis
    F4 = (8i + 12j + 4k)N
    Find the resultant


    3. The attempt at a solution
    I use 10cos37/sin37 for F1
    I use 15cos0/sin0 for F2

    But I don't how to use F3
    and F4

    Please help thankyou guys!
     
  2. jcsd
  3. Aug 4, 2015 #2

    BvU

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Write all three as ## \ \ a \; {\bf \hat\imath} + b\; {\bf \hat \jmath} + c\;{ \hat k}\ \ ## and add up the components.
    Make a sketch.
     
  4. Aug 4, 2015 #3
    hmmm I'll get the magnitude of it?
    I got 14.9666
     
  5. Aug 4, 2015 #4
    Help pls thankyouuuu
     
  6. Aug 4, 2015 #5

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Not right.

    Please follow the suggestion of BvU.

    Show your work.
     
  7. Aug 4, 2015 #6
    Can you please guide me in understanding f3 and f4? Thankyou!!
     
  8. Aug 4, 2015 #7

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    I assume the unit vectors are aligned as follows:

    ## \hat{i} \ ## points East.

    ## \hat{j} \ ## points North.

    ## \hat{k} \ ## points upward.

    Is that what is meant for F3 & F4?
     
  9. Aug 4, 2015 #8
    Soooooo I'll just CA3ZgMS.png ????
     
  10. Aug 4, 2015 #9

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    That's a rather incomplete description of what to do.

    Add all the vectors component by component.

    What form should you use for the resultant?
     
  11. Aug 4, 2015 #10
    Okay wait
     
  12. Aug 4, 2015 #11
    Btw how could I get the component of F3 and F4 that is my question , I know how to get the compnent of F1 and F2 you use xcosΘ and xsinΘ.
     
  13. Aug 4, 2015 #12

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    They are already given.
     
  14. Aug 4, 2015 #13
    So you mean to say
    i = x component
    j = y component
    k = z component
    ???
     
  15. Aug 4, 2015 #14

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Yes
     
  16. Aug 4, 2015 #15
    F3 = 14 N toward the negative z-axis what about this? Can you please translate this to me
     
  17. Aug 4, 2015 #16

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    What would be your interpretation of 5N to the West?, for example.
     
  18. Aug 4, 2015 #17
    I say it as 5N 0 degrees from the x-axis
     
  19. Aug 4, 2015 #18

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    How about 180° ?

    In other words, that's 5N in the direction of -x . that is to say, toward the negative x axis.
     
  20. Aug 4, 2015 #19
    Okay so "F3 = 14 N toward the negative z-axis" - What degree? Bc I'm aware of x-axis and y-axis. But I have problems dealing with z-axis
     
  21. Aug 4, 2015 #20

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Like you said in post #13:
    ## \hat{i} \ ## is in h x direction, etc.

    The vector ##\displaystyle \ (5\hat i-7\hat j+3\hat k\, )\text N\ ## has an x-component of 5N, a y-component of -7N, and a z-component of 3N .
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Given the concurrent forces, Determine the resultant
  1. Concurrent forces (Replies: 3)

  2. Concurrent forces (Replies: 5)

Loading...