Graphs in Practical Situations

What is Graphs in Practical Situations?

The use of graphs to represent real quantities, where the gradient and the area beneath the line both carry physical meaning fixed by the units of the axes. On a distance-time graph the gradient is speed and a horizontal section means stationary; on a speed-time graph the gradient is acceleration and the area beneath the graph is the distance travelled. Where the graph curves, an instantaneous rate is estimated by drawing a tangent at the point and finding the gradient of that tangent from two widely separated points on it. A conversion graph instead turns one unit into another by reading from one axis to the line and then to the other axis, and it need not pass through the origin.

This definition is part of the Algebra and Graphs chapter in Cambridge O Level Mathematics (Syllabus D).

Concepts related to Graphs in Practical Situations

• gradient as rate
• distance–time
• speed–time
• area under a graph
• tangent
• conversion graph