Turn on thread page Beta
    • Thread Starter
    Offline

    11
    ReputationRep:
    If I'm dividing a number (with no uncertainty) by a value with uncertainty, to get my final value, what rules do I follow to get the uncertainty in the final value?

    Ive tried:
    1. dividing the number by the uncertainty
    2. dividing the uncertainty in the value by the uncertainty, and then multiplying it with the final value

    But I'm not sure which one is correct (if either of them are). Thanks!
    Offline

    17
    ReputationRep:
    So when u multiply or divide u add the percentage uncertainties. So imagine that the number with no uncertainty has 0% uncertainty.

    If u know the uncertainty of the other number u can add these two uncertainties together to get the final percentage uncertainty.

    Then its just a matter of converting from percentage to absolute which should be fairly straight forward.
    Posted on the TSR App. Download from Apple or Google Play
    Offline

    17
    ReputationRep:
    (Original post by IDontKnowReally)
    If I'm dividing a number (with no uncertainty) by a value with uncertainty, to get my final value, what rules do I follow to get the uncertainty in the final value?

    Ive tried:
    1. dividing the number by the uncertainty
    2. dividing the uncertainty in the value by the uncertainty, and then multiplying it with the final value

    But I'm not sure which one is correct (if either of them are). Thanks!
    See above👊🏾
    Posted on the TSR App. Download from Apple or Google Play
    • Thread Starter
    Offline

    11
    ReputationRep:
    (Original post by Shaanv)
    So when u multiply or divide u add the percentage uncertainties. So imagine that the number with no uncertainty has 0% uncertainty.

    If u know the uncertainty of the other number u can add these two uncertainties together to get the final percentage uncertainty.

    Then its just a matter of converting from percentage to absolute which should be fairly straight forward.
    This is the alevel method right?
    Offline

    17
    ReputationRep:
    (Original post by IDontKnowReally)
    This is the alevel method right?
    Only one method for this question as far as im concerned, but yh it will work at a level.
    Posted on the TSR App. Download from Apple or Google Play
    • Thread Starter
    Offline

    11
    ReputationRep:
    (Original post by Shaanv)
    Only one method for this question as far as im concerned, but yh it will work at a level.
    is there a method using just the absolute uncertainties?
    Offline

    17
    ReputationRep:
    (Original post by IDontKnowReally)
    is there a method using just the absolute uncertainties?
    Not in this instance, if ur adding or subtracting two numbers with uncertainty u use absolute uncertainties. If ur multiplying or dividing u use percentage uncertainties.
    Posted on the TSR App. Download from Apple or Google Play
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: November 13, 2017

3,327

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should predicted grades be removed from the uni application process

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

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