FARM MOTORS 315 



product of the force in pounds by the distance in feet traveled 

 in one minute be 33,000, one horsepower of work would be 

 done. In measuring horsepower it is customary to determine 

 the number of foot pounds of work done in a minute and 

 divide by 33,000. For example, suppose a horse walks 165 

 feet per minute and exerts a pull of 200 pounds on his traces; 

 then the horsepower developed will be: 



200X165 



= 1 horsepower 



33,000 



QUESTIONS 



1. What is energy? 



2. What is the function of a motor? 



3. Explain the two general forms of energy. 



4. What are the principal sources of energy? 



5. Name the most important, farm motors. 



6. What is a prime mover? 



7. What is a force? 



8. How may a force be illustrated? 



9. Illustrate resultant and component forces. • 



10. Define work. 



11. In what units is work measured? 



12. Define power. 



13. What is the common unit of power and what is its equivalent? 



