Here is a document to help you in your physics paper 3 exam.
If you read it, understand it, and then use it when you go over the previous paper 3 specimen and 2017 paper 3 (which is available from Tuesday May 8th 2018), you will be in an excellent position to tackle paper 3. It covers errors, uncertainties, graphs…..
All of the questions in paper 3 are directly based on the information in this document, so you are mad to not spend at least a few hours doing this!
The document explains how to measure, or estimate, the uncertainty in any measurement that you may make, be given in an exam, or calculate from other data.
It explains how the absolute and percentage error change when you make repeated measurements.
It covers error bars on graphs, and how to calculate uncertainties in lines of best fit.
It goes over how to combine uncertainties when using measurements in an equation to calculate something else.
It tells you how to spot anomalous results and how to deal with them.
There is then a great section on how to get straight line graphs from any equation, no matter how complicated it is.
Finally a list of terms used in the practical side of physics are given, with a good explanation of each one.