1. Torque Rotational Motion

2. Torque  Forces that cause objects to rotate  Two Characteristics that contribute to the effectiveness of torque: Magnitude of force  Increase force – increase torque- increase angular acceleration (F = ma) Where the force is applied

3. Example: Opening a Door  Not all of the forces will create a torque and cause the door to rotate. Which force will create a torque?

4. Formula for Torque  Torque = (sinθr)F Torque - Lever arm – r (m) Force – F (N) Angle – θ Unit for Torque is Nm

5. Net Torque and Direction  Net Torque - sum of all torque acting on one object  Direction – If the force causes clock-wise rotation, the Torque is negative If the force causes counterclockwise rotation, the Torque is positive

6. Sample problem  Calculate torque for all forces (add angles and distances)

7. Sample problem #1 If pulley radius = 5 cm find torque

8. Sample Problem #2 F 1 = 10N, F 2 = 15 N what is net torque

9. Sample Problem #3  Find Net Torque