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. C = Pivot Point or Center of rotation FT A B C Torque arm Torque armWA
C = Pivot Point
or Center of rotation WB

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. 6 m 4 m TorqueA = WA x 6 m TorqueB = WB x 4 m FT Torque arm Torque armC
TorqueA = WA x 6 m
TorqueB = WB x 4 m WA WB

12. A TorqueA = WAAcosa TorqueB = WBBcosb FT B WB WA Torque Arm A
Torque Arm B A
TorqueA = WAAcosa
TorqueB = WBBcosb WA

13. FN = FA sin a FN FA a a
l sin a
Torque =FAl sin a

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

15. A person ties a rope to one end of a 10
A person ties a rope to one end of a 10.0 m I-beam & tries lift it by pulling with 2500 N at 37o from horizontal