The phrase "first law of motion" is spelled /fɜːst lɔː əv ˈməʊʃ(ə)n/ in IPA phonetic transcription. The "f" is pronounced as /f/, the "i" as /ɜː/, the "r" as /r/, and so on. The word "motion" is pronounced with a silent "t" (/ˈməʊʃ(ə)n/). This law, also known as the law of inertia, states that an object at rest will remain at rest and an object in motion will remain in motion with a constant velocity unless acted upon by an external force.
The first law of motion, also known as Newton's first law or the law of inertia, is a fundamental principle in classical physics that describes the behavior of objects in the absence of external forces. Proposed by Sir Isaac Newton in his work "Philosophiæ Naturalis Principia Mathematica" in 1687, this law states that every object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
According to the first law of motion, an object at rest tends to stay at rest, while an object in motion tends to stay in motion with the same speed and direction. This concept can be referred to as "inertia." Inertia is the property of matter that resists changes in motion. It is important to note that Newton's first law applies only to objects that are not subject to any external influences.
This law has significant implications in understanding the motion of objects and is a cornerstone of classical mechanics. It serves as a fundamental principle when predicting and explaining the behavior of various physical systems. The first law of motion forms the foundation for subsequent laws, such as the second law of motion (F=ma) and the third law of motion (action-reaction principle).