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Homework Help: Help with algebraic equation

  1. Oct 9, 2007 #1
    Basic Tension question- 5 kg block hanging from a string with one side at 30 degrees and the otherside at 45 degrees.

    Gravity assumed at 10 m/s2 (in the book)

    I got to:
    T1(cos 30)-T2(Cos45)=0 for the total forces in the x direction and
    T1(sin 30) + T2(sin 45)-(50 N)= 0 for the y direction

    I know im supposed to use algebra but i never was very good with numbers. How I got into AP physics, I'll never know! Thanks in advance!
  2. jcsd
  3. Oct 9, 2007 #2
    doing good. you have two unknowns in one equation. how about some rearranging to evaluate for one T and using some substitution?

    Hint: What is T1 equal to? (not asking for the tension value)
  4. Oct 9, 2007 #3
    hmmm t1= t2 (cos 45)/cos 30)

    So now I have T2((cos45)/(cos30))-T2Cos45

    For which I get .8164965809 hmmmmm where did i go wrong
  5. Oct 9, 2007 #4
    Close, but not quite. You're right:

    T1 = T2(cos45)/(cos 30)

    now take this and use it for the T1 in the other equation, then solve for T2. You should be good to go.
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