Physics U6

Physics U6

1. What is an accurate measurement?

   • A measurement which is close to the true or accepted value.

2. How can accurate measurements be referred?

   • Textbook. data tables and the internet
     • However, internet sources must be checked for authenticity and the influence of biased.

3. What is the type of error which leads to inaccuracy?

   • Systematic errors

4. What is primary data?

   • Data obtained when doing practical experiments

5. What is secondary data?

   • Data obtained from another source such as the Internet
     • Secondary data can be used to find the accuracy of primary data.

6. What is anamolous data?

   • Readings that fall outside the normal or expected range of measurements
   • When is anamolous data ignored?
     • calculating the avg.
     • Calculating the uncertainty
     • Plotting a graph

7. Average values

   • Why do we take them?
     • It gives us a reliable value from trials we have carried out.
   • Why should the rounding of the average value be the same as the raw data?
     • The average value is derived from the raw data. Therefore, it is impossible for the average value to be more precise than the raw data.

8. How can an experiment be valid?

   • If all the variables are controlled expect the variables which are being investigated
   • How does validity differ with accuracy?
     • A valid experiment would have its varibales controlled apart from those being investigated. An accurate experiment would give primary data which is similar to secondary data.

9. What are the three errors?

   • Systematic
     • Errors in the instrument.
       • Instrument needs to be recalibrated.
   • Random
     • Errors due to humans. Ex: Parallax
       • Can be minimized by repeating
   • Zero
     • Metre does not have zero as its initial value
     • Can be minimized by setting the value as 0

10. What is resolution?

    • The smallest reading that an instrument can measure.
    • Metre rule - 1mm Venier Calliper - 0.1mm Micrometer - 0.01mm Digital devices - 2.d.p.