Physics - Introduction to Physics

• What are the 7 SI base units?

  Kg, m, s, A, K, mol, cd.
• What is the definition of uncertainty?


  The interval that a value is said to lie within, with a given range of confidence
• How is absolute uncertainty expressed?


  In the units of the quantity measured
• What does absolute uncertainty represent in a set of results?


  Half the range of a set of results or half the resolution of a single reading
• What is the formula for percentage uncertainty?


  %U = (AU/mean value) x 100
• What is random error in measurements?


  Unpredictable variation between measurements that leads to a spread of values about the true value
• How can random error be reduced?


  By repeating the measurements
• What is systematic error?


  Causes all readings to differ from the true value and cannot be corrected by repeat readings
• What should be done to correct systematic error?


  A different technique should be used
• What is accuracy?


  How close a measurement is to the true value
• What is precision?


  A measure of how close a measurement is to the mean value
• What does precision indicate about random errors?


  It gives an indication of the magnitude of random errors but does not depict how close the true value is
• What does it meant by repeatable?


  The same experimenter can repeat a value using the same method and obtain the same value
• What does it mean for an experiment to be repeatable?


  An experiment can be repeated by different experimenters and still obtain the same results.
• What is resolution in the context of measuring instruments?


  Resolution is the smallest change of a quantity that causes a visible change in the reading recorded by a measuring instrument.
• What is an anomalous result?


  An anomalous result is a result that doesn't fit in with the other data.
• How can data be categorized?

  Data can be sorted into categories.
• What is continuous data?


  Continuous data can have any value on a scale.
• What is the difference between reading and measurement in experimental data?


  A reading requires one judgment, while a measurement requires two judgments.
• Give an example of a reading in experimental data.

  An example of a reading is a thermometer.
• Give an example of a measurement in experimental data.

  An example of a measurement is a protractor.
• What defines a valid result in an experiment?


  A valid result is one that answers the question it was intended to.
• What is a reliable result?


  A reliable result is one that can be consistently reproduced in independent experiments.
• Tip to remember to give answers In standard form!