Analysis of information sources in references of the Wikipedia article "힘 (물리학)" in Korean language version.
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.
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.
Force: Any external agent that causes a change in the motion of a free body, or that causes stress in a fixed body.
Force: Any external agent that causes a change in the motion of a free body, or that causes stress in a fixed body.