Plotting, lines of best fit, gradient and intercept, proportional or linear, the area under a graph and tangents to curves.
What you will learn
- Plot points and draw a line of best fit past an anomaly
- Find a gradient and an intercept, with units
- Tell directly proportional from linear
- Find the area under a graph
- Draw a tangent to find a rate (Higher)
Plotting and best fit
Independent variable across (x), dependent variable up (y).
Choose scales that use more than half the grid and go up in 1, 2 or 5 per square. Plot with small neat crosses.
A line of best fit (straight or a smooth curve) goes through the middle of the points with roughly as many above as below. Ignore an anomaly: do not draw the line through it.
Use a bar chart when the independent variable is a category (materials, colours), a line graph when it is a number.
The rest of this lesson and its 10 practice questions are locked.
In this lesson
- Plotting and best fit
- Gradient and intercept
- Areas and tangents
- Try it: Gradient and intercept on a plotter
10 practice questions, marked as you go; about 25 minutes in all.
Key terms
Line of best fit, Bar chart, Line graph, Intercept, Directly proportional, Linear, Interpolation
In this unit: Required practicals, maths skills and the equations
The skills every physics paper tests: units and standard form, uncertainty and errors, planning, graphs, the equations and the required practicals side by side.
- Units, prefixes and standard form
- Measurements, uncertainty and errors
- Variables, planning and risk
- Graphs: gradients, intercepts and areas
- The equations: learn, choose and rearrange
- The required practicals side by side
- Equation list B: recall and the formulae sheet
- Equation list C: word equations, recall and the equation sheet