Results 1 to 6 of 6

Math Help - unit conversion help

  1. #1
    Super Member
    Joined
    Sep 2008
    Posts
    607

    unit conversion help

    I have been given the density of milk =  990 kg m^{-3}

    and a volume of  3000 Litres h^{-1} I need to work out the
    mass.


    I know  \rho\\\\\\\\\\\\( kg m^{-3} ) = \frac{m( kg)}{ v( m^{3})}

    so I need to convert  3000 Litres h^{-1} to meters,

    can some please check my working.

    1L = 1000 ml

    1 ml = 1cm

    1m = 100cm

     \frac{3000 L}{1 h } \times \frac{1000ml}{1L} = \frac{3000000 ml}{h}  = \frac{3000000 cm}{h}

      \frac{3000000 cm}{h} \times \frac{1m}{100cm}  = \frac{30000 m}{h}

    to get m^{3} =  (\frac{30000}{h})^{3} = 2.7 \times 10^{13} m^{3} h^{-1}

    so   m kg = 990 kg m^{-3} \times 2.7 \times 10^{13} m^{3} = 2.673 \times 10^{16} kg

    is this correct ?
    Last edited by Tweety; October 19th 2010 at 01:21 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,621
    Thanks
    426
    Quote Originally Posted by Tweety View Post
    I have been given the density of milk =  990 kg m^{-3}

    and a volume of  3000 Litres h^{-1} I need to work out the
    mass.


    I know  \rho\\\\\\\\\\\\( kg m^{-3} ) = \frac{m( kg)}{ v( m^{3})}

    so I need to convert  3000 Litres h^{-1} to meters,

    can some please check my working.

    1L = 1000 ml

    1 ml = 1cm

    1m = 100cm

     \frac{3000 L}{1 h } \times \frac{1000ml}{1L} = \frac{3000000 ml}{h}  = \frac{3000000 cm}{h}

      \frac{3000000 cm}{h} \times \frac{1m}{100cm}  = \frac{30000 m}{h}

    to get m^{3} =  (\frac{30000}{h})^{3} = 2.7 \times 10^{13} m^{3} h^{-1}

    so   m kg = 990 kg m^{-3} \times 2.7 \times 10^{13} m^{3} = 2.673 \times 10^{16} kg

    is this correct ?
    what do you mean by Litres h^{-1} ?

    litres by itself is volume ... 1 \, L = 10^3 \, cm^3 = 10^{-3} \, m^3

    so ... 3000 \, L = 3000 \cdot 10^{-3} \, m^3 = 3 \, m^3

    m = \rho \cdot V

    m = 990 \, \frac{kg}{m^3} \cdot 3 \, m^3 = 2970 \, kg
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member
    Joined
    Sep 2008
    Posts
    607
    Quote Originally Posted by skeeter View Post
    what do you mean by Litres h^{-1} ?

    litres by itself is volume ... 1 \, L = 10^3 \, cm^3 = 10^{-3} \, m^3

    so ... 3000 \, L = 3000 \cdot 10^{-3} \, m^3 = 3 \, m^3

    m = \rho \cdot V

    m = 990 \, \frac{kg}{m^3} \cdot 3 \, m^3 = 2970 \, kg

    Litres per hour

     \frac{3000 L}{h}

    thanks
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,543
    Thanks
    1394
    Then it is not volume, it is a rate of flow.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member
    Joined
    Sep 2008
    Posts
    607
    Quote Originally Posted by HallsofIvy View Post
    Then it is not volume, it is a rate of flow.
    But I can still use it to work out the mass?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,621
    Thanks
    426
    Quote Originally Posted by Tweety View Post
    But I can still use it to work out the mass?
    ... you get kg/hr
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. unit conversion help
    Posted in the Algebra Forum
    Replies: 4
    Last Post: October 10th 2010, 03:33 AM
  2. Unit Conversion
    Posted in the Algebra Forum
    Replies: 3
    Last Post: September 9th 2010, 05:48 PM
  3. unit conversion
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 3rd 2009, 02:17 PM
  4. unit conversion
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: September 8th 2008, 07:06 PM
  5. unit conversion
    Posted in the Math Topics Forum
    Replies: 1
    Last Post: June 6th 2008, 02:30 PM

Search Tags


/mathhelpforum @mathhelpforum