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    I'm struggling with combining uncertainties.
    e.g. If I were to find the volume of a cone and its uncertainty, and I'm given that diameter of base = 15 plus/minus 0.1
    height = 30 plus/minus 5

    I can find the volume but what would be the uncertainty?


    Thanks in advance
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    (Original post by IAmTheChosenOne)
    I'm struggling with combining uncertainties.
    e.g. If I were to find the volume of a cone and its uncertainty, and I'm given that diameter of base = 15 plus/minus 0.1
    height = 30 plus/minus 5

    I can find the volume but what would be the uncertainty?


    Thanks in advance
    If this is at A-Level
    Find the % uncertainty in the quantities.
    Then for quantities you multiply or divide, add the % uncertainties to find the total % uncertainty in the answer.
    If you raise a value to a power, multiply the % uncertainty by the power.
    eg squaring a quantity doubles the % uncertainty.
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    (Original post by Stonebridge)
    If this is at A-Level
    Find the % uncertainty in the quantities.
    Then for quantities you multiply or divide, add the % uncertainties to find the total % uncertainty in the answer.
    If you raise a value to a power, multiply the % uncertainty by the power.
    eg squaring a quantity doubles the % uncertainty.

    Thanks a lot! But when I'm working out uncertainty of r^2 , what's the uncertainty of r? because I'm given diameter and not the radius. Would radius be 7.5 plus/minus 0.05?
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    (Original post by IAmTheChosenOne)
    Thanks a lot! But when I'm working out uncertainty of r^2 , what's the uncertainty of r? because I'm given diameter and not the radius. Would radius be 7.5 plus/minus 0.05?
    If you are given d and need to find r, the % uncertainty in r is the same as it was in d
    The actual uncertainty in r is half what it was in d.
    So yes, it's ±0.05 if it was ±0.1 in d
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    (Original post by Stonebridge)
    If you are given d and need to find r, the % uncertainty in r is the same as it was in d
    The actual uncertainty in r is half what it was in d.
    So yes, it's ±0.05 if it was ±0.1 in d
    Thank you
 
 
 
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