In [[physics]], '''motion''' means a constant change in the location of a [[body]]. Change in motion is the result of applied [[force]]. Motion is typically described in terms of velocity, acceleration, displacement, and [[time]].[http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html] An object's velocity cannot change unless it is acted upon by a [[force]], as described by Newton's first law. An object's [[momentum]] is directly related to the object's [[mass]] and [[velocity]], and the total momentum of all objects in a closed system (one not affected by external forces) does not change with time, as described by the [[law of conservation of momentum]]. | In [[physics]], '''motion''' means a constant change in the location of a [[body]]. Change in motion is the result of applied [[force]]. Motion is typically described in terms of velocity, acceleration, displacement, and [[time]].[http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html] An object's velocity cannot change unless it is acted upon by a [[force]], as described by Newton's first law. An object's [[momentum]] is directly related to the object's [[mass]] and [[velocity]], and the total momentum of all objects in a closed system (one not affected by external forces) does not change with time, as described by the [[law of conservation of momentum]]. |