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Homework Help: Highschooler Needs Help

  1. Jan 15, 2006 #1
    Hey I have this question about vectors that I can't solve. Can someone explain it to me?

    Vector A is 1550 25 degrees North of East. Vector B is 41 East of South. Vector C was 35 North of West. A+B+C=0. Find B and C.
     
  2. jcsd
  3. Jan 15, 2006 #2
    break your vectors into components when you add up your X and Y components (SEPARATELY) of all teh vectors you should get zero.
     
  4. Jan 15, 2006 #3
    Thats the problem I got

    1550sin 25 +Ysin 35-xsin49=1550cos25-Ycos35+Xcos49

    but I get like 5000 and 6000 for values of X and Y....
     
  5. Jan 15, 2006 #4
    who are X and Y. Can you use B and C like you use in your question please

    also you havent got ALL the signs correct.
    Assume a specific coordinate system with either up or down to be positive and left or right to be positive
     
  6. Jan 15, 2006 #5
    sorry, im just too used to using X and Y, Ok B and C it is.
    Assuming Up and Right is Positive and Left and Down is negative.
    Vector A, being 25 N of E, would be in the 1st quadrant and so both its components are positive.
    Vector B woudl be in the 4th quadrant. So its Y values would be negative and X values would be positive.
    vector C woudl be in the 2nd quadrant so its X compment woudl be negative and Y component woudl be positive.

    1550sin 25 + Csin 35- Bsin49=1550cos25 - Ccos35 + Bcos49=0
     
  7. Jan 15, 2006 #6
    ok now you can get two equations from that equality... solve or B and C like simulatenous equations

    Your answers have to be right... if you do the math correctly
     
  8. Jan 15, 2006 #7
    no i get B=5548.6 and C=6158
     
  9. Jan 15, 2006 #8
    do es any1 get a different results when doing the math? I like triple checkd this
     
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