1. DETERMINATION OF TORQUE

2. DEFINITION OF TORQUE

3. Rotating a door
Where is the best place to apply force to open the door?
How does the direction of force relate to the axis of rotation?

4. Torque 4

5. Big ideas What is torque?
What are examples of forces exerting torque in real life? 5

6. Big ideas How is torque calculated? What is the lever arm?
What is the application angle? 6

7. Torque Is a measure of how effectively a force causes rotation.
A measure of a force’s ability to cause rotation
Generated by an application of force on an object that does not go through the center of mass, axis of rotation 7

8. Application of Torque can result in object changing the rate of spin

9. Torque Units are Nm Not Joules (no displacement)
Direction (clockwise, counter clockwise) 9

10. Torque math T (Curved top) Units Nm (not Joules) T = rFsinΘ
R means______________
F means _____________
Θ means ______________ 10

11. Torque 11

12. How to calculate the torque
Need:
Size of force applied = F
Distance between application of force and pivot point (lever arm length = r )
Angle between force and lever arm (use the smaller of the two angles = Θ) 12

13. Torque is larger when: A larger force is applied
The length of the lever arm is increased
The angle between force and arm is 90° 13

14. TYPES OF PROBLEMS INVOLVING TORQUE

15. Equilibrium of large objects
Not only must all forces on object be balanced
The torques on the object must be balanced as well

16. See-saws and art mobiles
Example problem

17. Homework, readings
Read
Try problem 11,13,15 on pg 203