1. Physical Science Applications in Agriculture Unit Physical Science Systems

2. Problem Area Agricultural Mechanics and Machine Systems

3. Safe Handling and Loading: Balance and Center of Gravity Lesson

4. What is a roll-over? Discuss tractor safety and rollover protection. Anyone personally aware of tractor rollovers. Discuss loading and transport. Have any of them dumped a load or heard of someone who has dumped a load?

5. Learning Objectives 1.Define stability. 2.Explain the center of gravity. 3.Calculate the center of gravity.

6. Terms Balance Center of gravity Equilibrium Stability www.cdc.gov/ www.galleri-bjorn.dk/.../ pages/John%20Deere4.htm

7. What is stability? Stability –Refers to a condition of balance. Center of gravity is critical to stability. If an object is tipped, but will return to its original position when released, it is in stable equilibrium. www.alpaca-info.com/ranch.htm

8. What is stability? For a stable equilibrium condition, a plumb line dropped from the center of gravity will fall within the base of the object. www.safetyline.wa.gov.au/.../lecture78/l78_03.asp

9. What is stability? If an object is tipped to a point where a plumb line attached to the center of gravity falls outside its base, an unstable equilibrium condition exists. www.safetyline.wa.gov.au/.../lecture78/l78_03.asp

10. What is stability?

11. What is center of gravity? Center of gravity –Point at which all parts or areas of a body are balanced. Balance –Stability or equilibrium iareh.usask.ca/rhep/.../slide0004.htm

12. THE CENTER OF GRAVITY ON A TRACTOR

13. What is center of gravity? The typical tractor has its center of gravity located between the front and rear wheels behind the midpoint of the tractor’s length and above the axle height. Center of gravity of an object will always seek the lowest possible position. If tipping an object lowers the center of gravity, the object will not return to its original position.

14. What is center of gravity? www.alpaca-info.com/ranch.htm

15. Where is the center of gravity located on a tractor? Center of gravity of an object determines the stability of that object.

16. Where is the center of gravity located on a tractor? The center of gravity will always seek the lowest position possible; therefore great care must be taken when loading or hitching to prevent rollover. The external forces acting on a tractor pulling an implement can be quantified and analyzed.

17. Where is the center of gravity located on a tractor? Hitch height is an important variable in stability. 1.If hitch height is too high, the hitched tractor is not in equilibrium. 2.Hitching at a lower point or weighing the front of the tractor can prevent unsafe rollover conditions from occurring.

18. Where is the center of gravity located on a tractor?

19. The object will be stable if a plumb line dropped from the center of gravity passes through the base of the object.

20. Review/Summary What is stability? What is center of gravity? Where is the center of gravity located on a tractor?