Kinematics of a particle - Curvilinear motion of cylindrical components

steven86

hi guys,

I have a question about the names of parts in the formula for accelerating a partical using polar coordinates.

The formula for acceleration is:

a=a_ru_r+a_{[tex]\theta[/tex]}u_{[tex]\theta[/tex]}

where:
a_r=r"-r[tex]\theta[/tex]'²
a_{[tex]\theta[/tex]}=r[tex]\theta[/tex]"+2r'[tex]\theta[/tex]'

In these two equations
r" occurs due to exdending or shortening the arm
r[tex]\theta[/tex]'² occurs due to the centrifugal force
r[tex]\theta[/tex]" occurs due to the angular acceleration
but how is this term called? : 2r'[tex]\theta[/tex]'