LuduminaFM-03 · FM-U1 · Planned
Resultants on a line
Learning objectives
Calculate a signed resultant; identify balanced forces on one object.
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; MS1c,3c.
Needs firstFM-01
Explanation
The resultant combines all forces on one chosen body. Equal opposing forces on that body give zero resultant. This tells us its velocity does not change; it does not say the body must be stationary or that no forces act.
Concepts, equations and units: Force N; choose a positive direction; add/subtract collinear vectors.
Prediction, demonstration and game exercise
Predict, observe, explain
Predict a tug/cart outcome from force readings; demonstrate zero and nonzero resultants.
Planned learner game exercise
Set opposite thrusters to achieve target net forces while retaining individual arrows.
Independent practice
Four signed-resultant problems and one explanation of zero resultant.
Original practice example · Shared
A cart has 12 N right and 7 N left. Find resultant magnitude and direction.
Show working and model answer
Working / reasoning
Choose right positive: 12 − 7 = 5.
Answer
5 N to the right.
Exit check and success criteria
Three of four resultants correct including direction; balanced forces distinguished from absent forces.
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
Zero resultant means no forces; largest force alone decides the resultant.
Practical preparation
Optional force board/cart, AT2.
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.