Torque from weight on inclined beam Steps:

• Distance from pivot to 24kg child: half of 3.2m = 1.6m.
• Weight of child: 24kg × 9.8m/s² = 235.2N.
• Moment arm: horizontal distance = 1.6m × cos(20°) ≈ 1.6m × 0.9397 = 1.5035m.
• Torque: 235.2N × 1.5035m ≈ 354Nm (rounded to 350Nm in options). Why C is correct:
• Torque equals weight times perpendicular distance to line of action (vertical), which is L cosθ per the moment definition for inclined supports. Why the others are wrong:
• A: Ignores g and angle; just 24×3=72.
• B: Uses full length without angle: 24×9.8×0.5≈130.
• D: Omits cos(20°): 24×9.8×1.6≈380. Final answer: C