Mistake Master · AP Physics C · Unit 5 · Topic 5.5 · Step-Through Animation
Balance Is Torque, Not Weight
A 40 N kid far out balances a 60 N kid sitting close — because a plank holds still when the torques cancel, not when the weights match. Torque is force times lever arm, it carries a sign, and full equilibrium keeps two books at once: ΣF = 0 and Στ = 0.
STATICS LAB
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