SKKU-Calculus-Sec-15-3 Independence of the Path, SGLee+오교혁


   15.3    Independence of the Path             by SGLee, HSKim, 오교혁

1-6. Determine whether or not the vector field is conservative. If it is conservative, find a potential of .

 

1. 

 

     Not conservative, since curl.







2. 

 

      Not conservative.







3. 

 

      Not conservative.







4. 

 

 

        Since, curl  is conservative.

              ―(1)

      Taking partial derivative of  with respect to , we get    . Hence from (1) we get

              ―(2),thus   ―(3)

      Now taking partial derivative of  with respect to  we get . Hence from (3) we get

            , a constant. Therefore, .







5. 

 

      Not conservative.







6. 

 

      Conservative, .







 7. Show that the vector field  is not conservative.

 

 







 Since curl is not conservative.

 8. Determine whether the force field  is a conservative field.

           http://matrix.skku.ac.kr/cal-lab/cal-14-2-5.html 

 

 




* 위의 명령어로  표현돤 결과는 vector 로 표현되서 보기 편하다. 

 Ans: , hence  is not conservative field.



 9. a. Prove that   is a conservative field.

           b. Find its scalar potential .

           c. Also find the work done in moving an object in this field from  to .

           http://matrix.skku.ac.kr/cal-lab/cal-15-2-6.html 

 

      Scalar potential .

      Work done.










 10. Find the total work done in moving a particle by a force field  

            along the curve  form  to .

            http://matrix.skku.ac.kr/cal-lab/cal-15-2-8.html 

 

 




                                

                                     Plenary Speaker at AMC 2013, Bexco, Korea

 

                                             Back to Part II