The Principle of Moments

Try these questions

5 questions from this lesson’s quiz. Start the lesson to answer them and see the right answers.

1. 1. Which statement correctly gives the Principle of Moments for a body in rotational equilibrium?

   • A. The sum of clockwise moments about any point equals the sum of anticlockwise moments about the same point
   • B. The total upward force equals the total downward force only
   • C. The heaviest weight must be placed furthest from the pivot
   • D. The sum of all forces on each side of the pivot must be equal

2. 2. A uniform metre rule is balanced at its 50 cm mark. A 6 N weight hangs at the 20 cm mark. What weight hung at the 90 cm mark will balance the rule?

   Type your answer (in N) in the lesson.

3. 3. A uniform plank is balanced on a pivot. Wanjiru, whose weight is 500 N, sits 1.5 m to the left of the pivot. Her brother Otieno weighs 750 N. How far from the pivot must he sit on the right for the plank to balance?

   Type your answer (in m) in the lesson.

4. 4. A uniform metre rule balances at the 50 cm mark. A 4 N weight hangs at the 10 cm mark. A 5 N weight is placed on the other side to restore balance. At which mark on the rule must it be placed?

   • A. 82 cm
   • B. 32 cm
   • C. 90 cm
   • D. 58 cm

5. 5. What name is given to the fixed pivot point about which a lever or beam turns?

   Type your answer in the lesson.

More in Moments and Equilibrium

• ▸Thermal Expansion of Gases
• ▸Thermal Expansion in Matter
• ▸Revision and Practical Assessment of Thermal Phenomena
• ▸Introduction to Moments and Turning Effects
• ▸Centre of Gravity of Regular and Irregular Laminae
• ▸States of Equilibrium
• ▸Factors Affecting Stability and Structural Design
• ▸Parallel Forces and Multiple Supports

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