LuduminaFM-04 · FM-U1 · Planned
Free-body diagrams and vector resolution
Learning objectives
Draw free-body diagrams; find angled resultants and components by scale drawing.
8463 §§4.5.1.4 / 8464 §§6.5.1.4
DfE single-science pp.35–37 / Combined pp.30–32. Evidence checked 30 September–1 October 2026. Skills: WS1.2; MS4a,5a,5b.
Needs firstFM-03; P0 scale diagrams
Explanation
Resolving a vector replaces it with components that together have the same effect. It does not add extra physical interactions. Use a consistent scale drawing to determine components or a resultant, measuring angles and lengths from the diagram.
Concepts, equations and units: N; vector scale, perpendicular components, equilibrium; no trigonometric calculation required.
Prediction, demonstration and game exercise
Predict, observe, explain
Resolve a diagonal tow force with a scale diagram; isolate one object before drawing forces.
Planned learner game exercise
Align ropes for an equilibrium cargo platform; construct the vector polygon on a grid.
Independent practice
Two scale-diagram tasks giving magnitude and direction; explain component equivalence.
Original practice example · Shared Higher
A scale drawing gives perpendicular resultant components of 3 cm right and 4 cm upward, with 1 cm = 2 N. Measure the resultant and angle.
Show working and model answer
Working / reasoning
The diagonal measures 5 cm; its angle is about 53° above right. Multiply the length by 2 N/cm.
Answer
10 N at approximately 53° above the rightward horizontal, obtained by scale drawing.
Exit check and success criteria
Correct diagram convention and both answers within declared drawing tolerance.
During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.
Misconceptions, practical links and mastery
Check these misconceptions
Components are extra forces; use sine/cosine as a required GCSE method; third-law pairs belong on one free-body diagram.
Practical preparation
Optional force-table preparation; not an RP.
Virtual preparation and revision only. Required hands-on activities and school records remain separate.
Proposed mastery
0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.