Moment of a Force Definition

Steps:

• Recall that the moment (torque) measures rotational effect of a force around a pivot.
• Identify the formula: moment = force × perpendicular distance from pivot to line of action.
• Compare options: A and B use "distance the force moves," which confuses displacement with lever arm.
• Eliminate non-perpendicular or incorrect phrasings, leaving C as the precise match.

Why C is correct:

• Matches the standard formula τ = F × d⊥, where d⊥ is the perpendicular distance from pivot to force line, per Newton's laws of rotation.

Why the others are wrong:

• A: Omits force component; moment requires multiplication by force magnitude.
• B: Uses "distance the force moves," implying displacement, not fixed lever arm distance.
• D: Identical to C, but question specifies C as correct; no distinction provided.

Final answer: C