Mechanics / Electrodynamics
January 11, 2013
Newton’s laws have been quoted from the Philosophiæ Naturalis Principia Mathematica published in 1687. It is interesting to note that Newton has given second law of motion in different way and currently used by scientists in somewhat different way. An example has been quoted illustrating that action and reaction are not equal and opposite. This demonstration is repeatable. Newton’s second law of motion reduces to first and third law if a =0 and F=0 (motion is un-accelerated). Thus it is called real law of motion. But under this condition the inertial mass is m = a/F = 0/0, which is not justified. The inertial mass will be non-zero if a>0, F>0 or motion is accelerated, which changes basic notion of motion.