Advanced/Notes 9.1
- 2. Conditions for Equilibrium • What are the conditions for equilibrium?
- 3. What if… • We look at a book sitting on a table • Is it moving?
- 4. Equilibrium • The book is experiencing forces but is not moving • It is in equilibrium • Latin for equal forces
- 5. Braces • The wire band around the teeth has a tension TF of 2.0 N along it. What is the resultant force on the highlighted tooth? • Draw a force diagram of the tooth.
- 6. Braces • The wire band exerts the FT in each direction along the wire. • Since the forces are equal and in opposite directions, the FR will be along the line that bisects the angle between them.
- 7. Braces • Call the direction of FR the y axis • What will be the sum of the forces in the x direction? • What will be the sum of forces in the y direction (FR)? • Result of this?
- 8. Equilibrium
- 9. Chandelier • Calculate the tension FA and FB in the two cords that are connected to the vertical cord supporting the 200 kg chandelier. • Draw a free-body diagram of what?
- 10. Chandelier • Pick the point where the three cords meet • Sum in the forces in the x and y direction • Resolve FA into components
- 11. Equilibrium
- 12. Equilibrium?
- 13. Equilibrium • The forces add up to zero, but… • The forces produce a net torque that will rotate the object • Couple: A pair of equal forces acting in opposite directions but at different point in on object
- 14. Equilibrium
- 15. Lever • A bar is placed over a small rock to act as a lever on the large rock • The lever should allow a smaller FP • What if FP is still not large enough?
- 17. Homework • Read Section 9.1