STATIC EQUILIBRIUM AND ROTATIONAL QUANTITIES.pptx

STATIC EQUILIBRIUM AND ROTATIONAL QUANTITIES

1. STATIC EQUILIBRIUM

2. STATIC EQUILIBRIUM Static equilibrium occurs when an object is not moving and not rotating. Static means not removing Equilibrium means balance

3. STATIC EQUILIBRIUM Examples: A seesaw balanced with equal weights A hanging picture that does not tilt A bridge that stays steady

4. Conditions for Static Equilibrium

5. Conditions for Static Equilibrium For an object to be in static equilibrium , two conditions must be satisfied: 1. Forces must balance Total upward forces = downward forces

6. Conditions for Static Equilibrium 1. Forces must balance Examples: A ruler balanced on a pencil (pivot) does not move up or down when foces are equal

7. Conditions for Static Equilibrium 2. Torques must balance Total clockwise torque = total counterclockwise torque Torque = turning effect of a force

8. Conditions for Static Equilibrium 2. Torques must balance Formula: Torque = Force x Distance from pivot

9. Conditions for Static Equilibrium 3 . Understanding Torque Torque is the “twisting” effect that makes an object rotate.

10. Conditions for Static Equilibrium 3 . Understanding Torque Factors that affect torque: a. Force - The heavier the weight, the bigger the torque

11. Conditions for Static Equilibrium 3 . Understanding Torque Factors that affect torque: b. Distance from pivot – The farther the force is from the pivot, the bigger the torque

12. Conditions for Static Equilibrium 3 . Understanding Torque Examples: Pushes near the hinge – hard to open = small torque Push at the hande – easy to open = large torque

13. 4. Visual Examples Balanced Seesaw Forces are equal Torque are equal – Seesaw stays level

14. 4. Visual Examples B. Unbalanced Seesaw Left torque > Right torque – Left goes down

15. Conditions for Static Equilibrium 5. Vectors in Static Equilibrium Vectors are arrows that shows direction and magnitude of forces

16. Conditions for Static Equilibrium 5. Vectors in Static Equilibrium Examples: Downward = weight (force due to and magnitude of forces Upward arrow = support force (pivot or table)

17. Conditions for Static Equilibrium 5. Vectors in Static Equilibrium - When vectors cancel each other - object is balanced

18. Conditions for Static Equilibrium 6. Real – Life Applications Bridges and buildings ( forces and torques balanced) Seesaws and playground equipment Balancing scales in the laboratory

19. Conditions for Static Equilibrium 6. Real – Life - Tightrope walking (pole balances torques)

20. Questions: 1. What does static equilibrium mean?

21. Questions: 2. What are the two conditions for an object to be in static equilibrium?

22. Questions: 3. How can a lighter person balance a heavier person on a seesaw?

23. Questions: 4. Give an example of static equilibrium from your home or school.

24. Questions: 5. What is torque, in simple terms?