قانون الاحتكاك. شرح قانون الاحتكاك

"On the use and abuse of Newton's second law for variable mass problems"	Celestial Mechanics and Dynamical Astronomy
] Consequently, the mass of the system can not change during the time of interest	Hannah, J, Hillier, M J, Applied Mechanics, p221, Pitman Paperbacks, 1971• Cambridge UK: Cambridge University Press

قوانين الاحتكاك الانزلاقي

قانون قوة الاحتكاك — حساب قوة الاحتكاك: When the mass varies due to accretion or ablation, [an alternate equation explicitly accounting for the changing mass] should be used
تعريف قوة الاحتكاك: Any single force is only one aspect of a mutual interaction between two bodies
قوانين نيوتن للحركة: I]t is essential to deal with the same set of particles throughout the time interval[

Metaphysics Research Lab, Stanford University	Cambridge UK: Cambridge University Press
Quoting Newton in the Principia: It is not one action by which the Sun attracts Jupiter, and another by which Jupiter attracts the Sun; but it is one action by which the Sun and Jupiter mutually endeavour to come nearer together	I Bernard Cohen Peter M