PH03-04 Physics Coming soon
Free body diagrams (Higher)
PH03-04
This lesson is coming soon.
In this lesson
Draw a free body diagram showing every force acting on one isolated object, and read off it whether those forces are balanced.
What it covers
- Isolating ONE object, named out loud before anything is drawn, and rubbing everything else out
- The object drawn as a plain box or a dot, deliberately not as a picture of itself
- Every force drawn as an arrow starting at the object, labelled with what the force is AND what exerts it
- The four that cover almost every GCSE case: weight (always down, always from the Earth), the normal contact force (perpendicular to the surface), friction or drag (opposite the motion), and the applied push or the tension
- Only forces ACTING ON the isolated object go on its diagram - the forces it exerts on other things belong on their diagrams
- The boards' own limiter: QUALITATIVE ONLY. Arrow lengths show which force is bigger; no ruler, no scale, no measured value
- Reading balanced or unbalanced straight off the picture, and writing the resultant underneath in words
- A checking routine run out loud: does every arrow name an agent, and is any arrow's partner sitting on the same diagram
- Drawing the SAME situation twice, one diagram per object, so a viewer can see where the partner force went
Key words
For: AQA GCSE 8463, Edexcel GCSE 1PH0, OCR GCSE J249
On the specification
| Board | Spec | Statement |
|---|---|---|
| AQA GCSE 8463 | 4.5.1.4b | Resultant forces |
| Edexcel GCSE 1PH0 | 9.4 | Draw and use free body force diagrams |
| Edexcel GCSE 1PH0 | 9.5 | Explain examples of the forces acting on an isolated solid object or a system where several forces lead to a resultant force on an object and the special case of balanced forces when the resultant force is zero |
| OCR GCSE J249 | P2.2f | Describe examples of the forces acting on an isolated solid object or system |
| OCR GCSE J249 | P2.2g | Describe, using free body diagrams, examples where two or more forces lead to a resultant force on an object |
| OCR GCSE J249 | P2.2h | Describe, using free body diagrams, examples of the special case where forces balance to produce a resultant force of zero (qualitative only) |
For teachers
This GCSE Physics lesson teaches free body diagrams (Higher). By the end, students should be able to draw a free body diagram showing every force acting on one isolated object, and read off it whether those forces are balanced. It works through three worked examples and the mistakes examiners report.