Describing graphs

In A-level physics you are often presented with a graph and required to extract information from it. As well as calculating gradients and areas, you can read the trend of the graph to extract important information. Billy Townend looks at how you can describe a graph, and what it tells us about the mathematical link between variables

Being able to describe a graph and understand what information it is giving you is a vital skill in A-level physics. We can use graphs to get information from data points, and we can use them to calculate other quantities, such as gradients and areas, that have significance for the physics. The shape of the line also tells its own story.

Graphs may reveal a link between two variables. At the most basic level we can use graphs to see whether two variables are correlated. This is probably how you would have first learned how to describe graphs (Figures 1–3).