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Simple proportionality question

  1. Mar 20, 2012 #1
    Hey guys, simple question really:
    Given the equation
    Code (Text):
    v = (Gm/r)[SUP]1/2[/SUP]
    Is it wrong to say
    Code (Text):
    v is inversely proportional to r
    Or do you have to say
    Code (Text):
    v is inverslely proportional to r[SUP]1/2[/SUP]
     
  2. jcsd
  3. Mar 20, 2012 #2

    tiny-tim

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    Science Advisor
    Homework Helper

    hey hmvince! :wink:
    yes!!! :smile:
    you don't have to say "inverslely"! o:)
     
  4. Mar 21, 2012 #3
    I thought you did have to, cos if you dont it means v increases with r, instead of v decreases with r.
    Do you mean to say this?:
    v is directly proportional to r-1/2?

    Looking at your number of posts and recognitions I dont mean to say you are wrong, just trying to figure it out for myself!
     
  5. Mar 21, 2012 #4

    tiny-tim

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    Science Advisor
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    hi hmvince! :wink:

    yes, it's always best to ask until you're sure

    no point in losing even one mark in an exam by knowing the maths but not using the generally-accepted phrase! :smile:

    you can say

    v is proportional to r-1/2

    or

    v is inversely proportional to r1/2

    or

    v and r-1/2 are proportional

    or

    v and r1/2 are inversely proportional​

    (and you don't need "directly", since it adds no information … but it isn't actually wrong)
     
  6. Mar 21, 2012 #5
    Thankyou!
     
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