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Math Help - equation help

  1. #1
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    equation help

    T1 = \frac{mg}{\sin\alpha\:+\:\frac{\cos\:\alpha}{\cos\  :\beta}\sin\:\beta}

    \sin\:\alpha = 64
    \cos\:\alpha = 26
    \cos\:\beta = 39
    \sin\:\beta = 51

    i get the answer to 27.2587, am i doing this correct?

    mg = 49
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  2. #2
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    Quote Originally Posted by 1LISTEN View Post
    T1 = \frac{mg}{\sin\alpha\:+\:\frac{\cos\:\alpha}{\cos\  :\beta}\sin\:\beta}

    \sin\:\alpha = 64
    \cos\:\alpha = 26
    \cos\:\beta = 39
    \sin\:\beta = 51

    i get the answer to 27.2587, am i doing this correct?
    I get T_1 = \frac{981}{9800}\,m

    Edit:

    No I evaluate T_1 = 0.5

    T_1 = \frac{49}{64+\frac{26}{39}\cdot 51} = \frac{1}{2}
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  3. #3
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    sorry i forgot to add mg is 49N
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  4. #4
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    Sin (64)=sin Alpha
    cos (26)=cos alpha
    cos (39) = cos beta
    sin (51) = sin beta

    sorry for the confusion.
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  5. #5
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    I've re-done it.


    T1 = \frac{49}{\sin\left(64\right)\:+\:\frac{\cos\:\lef  t(26\right)}{\cos\:\left(39\right)}\sin\:\left(51\  right)}

    I get 27.2587
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  6. #6
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    T_1 = \frac{mg}{\sin(\alpha) + \frac{\cos(\alpha)}{\cos(\beta)}\sin(\beta)}

    Substitute the given values.

    \frac{42}{\sin(64) + \frac{\cos(26)}{\cos(39)}\sin(51)}

    Evaluate the trigonometric functions.

    \frac{42}{0.92 + \frac{0.647}{0.266} * 0.67}

    Perform multiplication and division (from left to right) in the denominator.

    \frac{42}{0.92 + 1.63}

    Perform addition in the denominator.

    \frac{42}{2.55}

    Perform division.

    16.471
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  7. #7
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    I get the following:

    \frac{49}{0.8988\:+\frac{0.8988}{0.7771}\times0.77  71} = 27.258
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  8. #8
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    e^(i*pi)'s Avatar
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    Do you mean degrees or radians? Angles without the degree symbol are usually assumed to be radians

    NOX Andrew has used radians where it appears you used degrees
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  9. #9
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    yes sorry, i am using degrees.

    Would you agree on the basis of using degree's that my answer of 27.258 is correct?
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  10. #10
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    Quote Originally Posted by 1LISTEN View Post
    yes sorry, i am using degrees.

    Would you agree on the basis of using degree's that my answer of 27.258 is correct?
    No, but you're very close. I get an answer of 27.25874754... but I rounded it off to 27 as all numbers are given to 2sf in the question.

    To 3dp as you did you'd still have to round that 27.258 to 27.259 because the next digit is a 7
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