Angular Momentum

 

Any rotating body has angular momentum about its center of mass G. Angular momentum depends on the reference point chosen.

 

• pure translation
• pure rotation
• general planar motion

 

Pure translation

 

Translation with repect to point O.

 

H_O = r_G/O x mv

 

Pure rotation

 

Rotation about fixed point O.

 

H_O = I_Oω

 

General planar motion

 

General planar motion with respect to the body's mass center.

 

H_G = I_Gω

 

General planar motion with respect to point O.

 

H_O = r_G/O x mv_G + I_Gω

 

• r_G/O x mv_G = component due to the translation of the body with respect to point O
• I_Gω = component due to the rotation of the body about its mass center