Torque Center of mass Center of gravity

1. Torque Center of mass Center of gravity

2. What is Torque? • Torque- the quantity that measures the ability of a force to rotate an object around some axis

3. Torque is a force that tends to cause a rotation. A force applied at a non-zero distance from an object's center will tend to rotate the object. • This is easily seen in real life. If a wrench is placed on a bolt and a force is applied to the end of the wrench, the bolt will turn. Amayaku.blogspot.com

4. If the same pulling force was applied directly to the bolt, it would not turn because the force's direction passes through the object's center. Amayaku.blogspot.com

5. Components of Torque • Torque depends on a force and a lever arm

6. Torque – Lever Arm The lever arm is the perpendicular distance from the axis of rotation to a line drawn along the direction of a force.

7. Torque is the product of force and distance. Units of Torque: Newton-meters or Foot-Pounds

9. Torque and Force distance

10. Caution: Homemade extensions are frowned on by safety experts.

11. Avoid over- or under-torqueing when assembling engine parts (or other machines). A torque wrench will permit tightening to the exact torque required.

12. Torque v Traction TRACTION can be defined as the friction between a drive wheel and the surface it moves upon. It is the amount of force a wheel can apply to a surface before it slips. A wheel will have different traction on different surfaces; as described above, the coefficient of friction is based on pairs of surfaces. (VEX Robotics Design Curriculum) 

13. When a torque is applied to a wheel, it applies a force along the ground.  However, one can imagine that if the wheel was spinning on ice, the wheel would slip and would not move forward.  The friction between the wheel and the ground is necessary to make it move forward, this is the tractive force.

14. To increase traction, one must either increase the coefficient of friction (grippier wheels) or increase the normal force acting on the wheel (heavier car or robot, or more weight on drive wheels).

15. Difference Between Torque and Work Torque is a force that tends to cause a rotation. Work is a measure of energy transfer between systems, which may or may not have been done by a force from torque.On a rotating shaft work is done by the force from torque. Amayaku.blogspot.com

16. Center of Mass • Center of mass – the point at which all the mass of the body is considered to be concentrated. (It is the average position of an object’s mass.)

17. Facts about Center of Mass – Dr. Awesome Physics • If an object is hit or pushed, and the point of contact is far away from the center of mass, the object will spin • If a strike or a push is applied into the center of mass, the object will not spin, and will move in the same direction as the applied force.

18. If an object does spin, the center of mass is located at the center of rotation. • If you hang an object from a string, the center of mass will be located directly belowthe string. Dr. Awesome Physics.com

19. If you balance an object on the tip of your finger, the center of mass will be located directly above the tip of your finger.

20. Center of Gravity • Center of Gravity – the average position at which the gravitational force acts on the body. • For most situations, the center of mass and the center of gravity are the same.