Explicit physics instruction
This investigation tests torque balance with a safe low-load lever model.
Use a safe lever simulation or light ruler model. Compare balancing distances for unequal forces; do not load furniture or unstable supports.
Preserve force values, distances, torque calculations, and one residual.
Core relation: τ=rF⊥ and Στ=0 in rotational equilibrium.
Worked example
Measured torques of +1.98 and −2.04 N·m leave a small −0.06 N·m residual, which should be compared with measurement uncertainty.
Guided question
Which measurement—force or lever arm—contributes most to your torque uncertainty?
Independent work
- Solve three torque or balance cases.
- Draw a pivot/lever-arm diagram.
- State one assumption or uncertainty.
Investigation / Data Lab
Use a safe lever simulation or light ruler model. Compare balancing distances for unequal forces; do not load furniture or unstable supports.
Evidence record: raw force/distance data, signed torques, residual, uncertainty, and revision.
Misconception check
A larger force does not always produce larger torque; lever arm and force direction matter.
Formative check
What two geometric features determine torque besides force magnitude?
Reveal response
Distance from the pivot and the force’s perpendicular component/direction.
Mentor evidence conference
Ask Archaemenes to audit pivot choice, torque signs, lever arms, and equilibrium assumptions.
Teacher guidance
Foundation: Calculate perpendicular torque.
Core: Solve multi-torque equilibrium.
Extended: Analyze stability and uncertainty in a lever model.