Center of Curvature - (continued)

 

                                  

 

Strategy for locating the center of curvature, C,  rc :

 

1.  First note that     rc  =  r  +  ρ en     where   r  =  xp(t)  i +  yp(t)  j

     where   r  locates the point on the path where the center of curvature is to be calculated

 

 

2.  To find  C  one needs to calculate  ρ  and   en .

 

 

3.  First find  en  by examining the change of  et  over a short period of time, dt.

 

 

                     

 

Summary:         en   =   det/dt/ |det/dt |         where  et  =  dr/dt / | dr/dt|

 

4.  Next find  ρ  using   an  =  v2 / ρ

 

     ap  =  d2r/dt2    and   v  =  | dr/dt |

 

Then    an  =        ap    en .              So    ρ  =  v2  /  an  

 

The result is    rc  =  r  +  v2 /an   en     which holds for space curves as well.

 

Click here for an example.

 

 

         


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