Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    how to calculate % uncertainty.what is the formula?:confused::confused:
    Offline

    3
    ReputationRep:
    (Original post by lopper)
    how to calculate % uncertainty.what is the formula?:confused::confused:
    Do you mean the percentage uncertainty in the value of a measurement due to the apparatus? If you do then it's generally:

    percentage \ uncertainty = \dfrac{smallest \ graduation \ of \ apparatus}{measured \ value} \times 100
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Star-girl)
    Do you mean the percentage uncertainty in the value of a measurement due to the apparatus? If you do then it's generally:

    percentage \ uncertainty = \dfrac{smallest \ graduation \ of \ apparatus}{measured \ value} \times 100
    The engineer obtained three sets of data. The values for the Young modulus were14.2, 14.7 and 15.1 GPa.Determine the average value and state its uncertainty
    Offline

    3
    ReputationRep:
    (Original post by lopper)
    The engineer obtained three sets of data. The values for the Young modulus were14.2, 14.7 and 15.1 GPa.Determine the average value and state its uncertainty
    Oh, I see - it is uncertainty in the average value of a measurement rather than due to the apparatus.

    In that case, have you determined the average value? By how much does the farthest value differ from the average?
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Star-girl)
    Oh, I see - it is uncertainty in the average value of a measurement rather than due to the apparatus.

    In that case, have you determined the average value? By how much does the farthest value differ from the average?
    14.7 Gpa
    Offline

    3
    ReputationRep:
    (Original post by lopper)
    14.7 Gpa
    Yes. Now look at the measured value - which is the one furthest from 14.7 Gpa?
    • Thread Starter
    Offline

    0
    ReputationRep:
    will the uncertanity be + or -1/2 range
    • Thread Starter
    Offline

    0
    ReputationRep:
    14.2 and nice the difference is equal to the uncertainty.
    Offline

    3
    ReputationRep:
    (Original post by lopper)
    14.2 and nice the difference is equal to the uncertainty.
    It is indeed. However, you are asked for the percentage uncertainty and this is the difference as a percentage of the mean value.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Star-girl)
    It is indeed. However, you are asked for the percentage uncertainty and this is the difference as a percentage of the mean value.
    thanks
    Offline

    3
    ReputationRep:
    (Original post by lopper)
    thanks
    You're welcome.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Did TEF Bronze Award affect your UCAS choices?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.