Data analysis

• What is uncertainty?

  Anything that may cause the value to differ from the true value
• What is the resolution of a measuring instrument?

  The smallest increment that produces a noticeable change in the value
• How do you combine uncertainties when adding values?


  Add the absolute uncertainty
• How do you combine uncertainties when subtracting values?

  Add the absolute uncertainties
• How do you combine uncertainties when multiplying values?

  Add the percentage uncertainties
• How do you combine uncertainties when dividing values?

  Add the percentage uncertainties
• How do you combine uncertainties when raising values to a power

  Multiply the percentage uncertainties by the power
• How do you calculate percentage uncertainty?

  (Uncertainty/measurement)

  ×100
• How do you calculate the uncertainty of repeat readings?

  Half the range of the measured values
• How do you calculate the uncertainty of a gradient?

  Draw steepest and shallowness line of worst fit, calculate the gradients and find the difference
• What is the unit used for distance?

  M, metre
• What unit is used for mass?

  Kg, kilogram
• What unit is used for time?


  S, second
• What unit is used for temperature?

  Kelvin, K
• What is the unit used for force?

  $Kgms^-2$
• What a systematic error?

  Will cause all results to be too high or low by the same amount each time
• What is a zero error?

  When a zero input doesn't produce a zero output on a measuring instrument
• What is noise?

  Random variations superimposed onto a signal output
• What is response time?


  The time to produce an output from an input
• What is a repeatable experiment?

  Where the same experiment can be carried out by the same person using the same method and similar results are obtained
• What is a reproducible experiment?

  It can be repeated by a different person with a different method and similar results are obtained