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    I've come across a question that seems like it should be relatively easy, but I've changed the numbers so no one gives me the actual answer and I can work it out for myself. Here's the question:

    If 0.2cm³ of oil spreads 60m², how thick is the oil layer?
    I feel like you would have to convert the 0.2 into m² and then divide it? But I'm not really sure, and if you do have to do the conversion then I'm not sure how to actually do that
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    0.2 is a volume (convert it to m3), 60 is an area. Divide former by latter to get a thickness

    Another hint: after conversion, the number to be divided is even smaller than 0.2
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    (Original post by shawn_o1)
    0.2 is a volume (convert it to m3), 60 is an area. Divide former by latter to get a thickness
    To convert cm³ to m³ would you just divide by 100?
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    Volume = length \times width \times height

    Therefore,

    Volume = area \times height \Rightarrow \frac{Volume}{Area} = Height

    Yes you're correct, as long as your units are consistent then it should be fine.
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    (Original post by Amefish)
    To convert cm³ to m³ would you just divide by 100?
    You divide it by 1003
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    (Original post by Amefish)
    To convert cm³ to m³ would you just divide by 100?
    You're dealing with a cubic unit so \frac{0.2}{100^{3}} = km^{3}
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    (Original post by ManLike007)
    You're dealing with a cubic unit so \frac{0.2}{100^{3}} = km^{3}
    Wait so how do I get to m³? When I get to m³, is it ok dividing that number by m² to get the thickness of the oil?

    So confusing! And what units would the thickness be in?
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    (Original post by Amefish)
    I've come across a question that seems like it should be relatively easy, but I've changed the numbers so no one gives me the actual answer and I can work it out for myself. Here's the question:



    I feel like you would have to convert the 0.2 into m² and then divide it? But I'm not really sure, and if you do have to do the conversion then I'm not sure how to actually do that
    You're completely correct about the general method, it seems like you just need to work out the conversion. The way I think about it is this:

    1  m^3 is 1m by 1m by 1m. This is the same as 100cm by 100 cm by 100cm which is  100^3 m^3 . Therefore the conversion is  1:100^3 .
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    (Original post by Amefish)
    Wait so how do I get to m³?
    cm^{3} to m^{3} you just divide by 100^{3}

    (Original post by Amefish)
    When I get to m³, is it ok dividing that number by m² to get the thickness of the oil?

    So confusing! And what units would the thickness be in?
    Yes, remember the equation, \frac{Volume}{Area} = Thickness (or height I guess), now in terms of units you get \frac{m^{3}}{m^{2}}=m therefore your unit for thickness is m
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    (Original post by ManLike007)
    cm^{3} to m^{3} you just divide by 100^{3}



    Yes, remember the equation, \frac{Volume}{Area} = Thickness (or height I guess), now in terms of units you get \frac{m^{3}}{m^{2}}=m therefore your unit for thickness is m
    Thanks a lot! I'll probably have some more questions in the maths forum soon, I'm preparing for my first uni lecture and I haven't done maths since GCSE
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    ManLike007 is this right?


    \frac{0.2cm^{3}}{100cm^{3}} = 2x10^{-7}m^{3}

    \frac{2x10^{-7}m^{3}}{60m^{2}} = 3.\dot{3}x10^{-9}m
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    (Original post by Amefish)
    ManLike007 is this right?


    \frac{0.2cm^{3}}{100cm^{3}} = 2x10^{-7}m^{3}

    \frac{2x10^{-7}m^{3}}{60m^{2}} = 3.\dot{3}x10^{-9}m
    Yes that seems about right. Also in the first line, it's 100^{3}cm^{3}, probably you forgot to write that.

    If you're wondering how to write \times and not x, it's just \times, just a little advice
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    (Original post by ManLike007)
    Yes that seems about right. Also in the first line, it's 100^{3}cm^{3}, probably you forgot to write that.

    If you're wondering how to write \times and not x, it's just \times, just a little advice

    Also, are there a specific limit of significant figures you're allowed to write as your final answer rather than recurring?
    Thank you! I only just discovered the realms of LaTeX in my actual answer I have converted it to nm and there are no recurring decimals, it's just because I changed the numbers for TSR there's no note about significant figures, but I'd assume it's 3.

    Also I was wondering if you could help me with something else?

    I know that 10^{4}m^{2} = 2.47 acres so if I do:

    \frac{10^{4}}{2.47}

    Would that give me the m or the m² in one acre?
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    (Original post by Amefish)
    Thank you! I only just discovered the realms of LaTeX in my actual answer I have converted it to nm and there are no recurring decimals, it's just because I changed the numbers for TSR there's no note about significant figures, but I'd assume it's 3.

    Also I was wondering if you could help me with something else?

    I know that 10^{4}m^{2} = 2.47 acres so if I do:

    \frac{10^{4}}{2.47}

    Would that give me the m or the m² in one acre?
    Yes that would give you one acre in m^{2}

    Just to explain,

    [10^{4} m^{2} = 2.47  acres] \div 2.47

    \frac{10^4}{2.47} = \frac{2.47}{2.47}

    4050m^{2} = 1 acre (to 3 sig. figs)

    Generally acres is a unit for land area so it'll never be in metre. It's quite to hard say why the units don't change, it's just regular division really unless you choose to change the power of ten i.e 1 \times 10^{-9}m \equiv 1nm
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    ManLike007 it seems I got the complete wrong answer. Super confused right now!
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    (Original post by Amefish)
    ManLike007 it seems I got the complete wrong answer. Super confused right now!
    Could you be a bit more specific by any chance?
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    (Original post by ManLike007)
    Could you be a bit more specific by any chance?
    I'm just going to see if I can work it out again so I can explain what went wrong
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    (Original post by ManLike007)
    Could you be a bit more specific by any chance?
    Basically this is a whole different approach.

     area \times height = volume

    So.. using "t" to mean thickness...

    60 \times t = volume

     cm^{3} \Rightarrow m^{3} = 1 \times 10^{-6}

    So get the amount of oil..

     0.2 \times 10^{-6} or.. 2 \times 10^{-7}

     \frac {0.2 \times 10^{-6}}{60} = thickness = 3.\dot{3} \times 10^{-9}

    The numbers are a bit messy here because I changed them for TSR, but this is the general method
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    (Original post by Amefish)
    Basically this is a whole different approach.

     area \times height = volume

    So.. using "t" to mean thickness...

    60 \times t = volume

     cm^{3} \Rightarrow m^{3} = 1 \times 10^{-6}

    So get the amount of oil..

     0.2 \times 10^{-6} or.. 2 \times 10^{-7}

     \frac {0.2 \times 10^{-6}}{60} = thickness = 3.\dot{3} \times 10^{-9}

    The numbers are a bit messy here because I changed them for TSR, but this is the general method
    So what’s wrong here? This is the same as yesterday’s answer. The method is the same as well, we both used the general equations
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    (Original post by ManLike007)
    So what’s wrong here? This is the same as yesterday’s answer. The method is the same as well, we both used the general equations
    Oh god, you're right! My answer for the actual question is completely different to what it should be! I must not have followed the method properly yesterday
 
 
 
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