Commonly Used Words. Arranged alphabetically, these sections include spelling, usage, punctuation and capitalization notes for specific words and phrases commonly used in the CSU. An entry without an explanation is simply to indicate the correct spelling of a word or words. A B-C D-F G-M N-S T-Z.
Noun. 1. Newton's first law of motion-a body remains at rest or in motion with a constant velocity unless acted upon by an external force. first law of motion, Newton's first law. law of motion, Newton's law, Newton's law of motion-one of three basic laws of classical mechanics.
Newton's First Law of Motion states that objects continue to move in a state of constant velocity unless acted upon by an external net force or resultant force. This law is an extension of Galileo's insight that constant velocity was associated with a lack of net force (see a more detailed description of this below).