rigid body kinematics

Another couple of interesting articles to share. Using some "mechanics" principles, researchers have reasoned that 100,000 years ago, kangaroos were too heavy to hop.

A while ago, a different group of researchers published the results of computer modelling (using genetic algorithms) that showed dinosaurs might have hopped and skipped as forms of locomotion! (But only if particularly happy?)

These articles might be good to share with undergraduate engineers for discussion in tutorials. There are issues to discuss with assumptions in both cases. 

   The concept of axis of of pure rotation  ( or instantatious center of rotation)  is a bit confusing. The text books in engineering mechanics( Irvin shames , Beer & Johnston etc) tells that the locus of points in a body, which is (are) having zero veloity.   This fits  well in case of a 2D motion. As a limiting case of this we are assuming the center of rotation is at inifinity for a rigid body moving in a straight line

Hi everybody! I'm glad to join iMechanica, just hope to contribute something of interest...and share our penchant for this fascinating subject with all of you