Working out the units?

  1. I am having a problem finding the correct SI unitsfor the quantity A?

    In the equation

    A=√(R/TY)

    That is A equals the square root of R divided by TY

    (not to good showing workings on the computer sorry)

    , the SI units of the quantity R are kg m^3 s^–2, the SI units of the quantity T are kg and the SI units of the quantity Y are m s^–2. What are the correct SI units for the quantity A?
     
    Last edited: Nov 8, 2011
  2. jcsd
  3. Mark44

    Staff: Mentor

    Both your notation and explanation are ambiguous.

    Is the expression on the right side this?
    [tex]\sqrt{\frac{R}{TY}}[/tex]
    or this?
    [tex]\frac{\sqrt{R}}{TY}[/tex]
     
  4. The first one R/ty all square root. Do apologise for the bad format
     
  5. Then, the units of A are meters.
     
  6. To clarify gsal's answer...

    You have the expression
    [tex]\sqrt{\frac{R}{TY}}[/tex]

    Simply, insert the units for each variable (in place of the variables):
    [tex]\sqrt{\frac{\frac{kg\cdot m^3}{s^2}}{(kg)(\frac{m}{s^2})}}[/tex]

    and simplify...
    [tex]\sqrt{\left(\frac{kg \cdot m^3}{s^2}\right) \left(\frac{s^2}{kg \cdot m}\right)}[/tex]

    kg and s2 cancel out, leaving
    [tex]\sqrt{\frac{m^3}{m}}[/tex]

    which is
    [tex]\sqrt{m^2}[/tex]

    or, more simply m
     
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