1. Torque

2. Center of Gravity The point at which all the weight is considered to be concentrated The point at which an object can be lifted w/o producing rotation

3. Center of Gravity In asymmetric objects, the center of gravity may not be the geometric center

4. Translational Equilibrium Occurs when an object is not accelerating

5. Rotational Equilibrium Occurs when an object is not rotating or the rotation is uniform

6. Torque The rotational effect of an object produced by a net force that is not applied to the center of gravity

7. WAWA WBWB A B C Torque arm C = Pivot Point or Center of rotation FTFT

8. Pivot Point Reference point from which to measure rotational forces

9. Torque Arm The length between the pivot point and the point where a force is applied

10. Torque The product of the applied force and the length of its torque arm:

11. WAWA WBWB A B C Torque arm 6 m 4 m FTFT Torque A = W A x 6 m Torque B = W B x 4 m

12. Torque Arm A WAWA WBWB Torque Arm B A B Torque A = W A Acos  Torque B = W B Bcos    FTFT

13. FAFA FNFN  F N = F A sin   l sin  Torque =F A l sin 

14. Calculate the torque on a 250 cm rod with a pivot point at one end and a 500.0 g object sitting on the other end

15. A person ties a rope to one end of a 10.0 m I- beam & tries lift it by pulling with 2500 N at 37 o from horizontal