What is another word for first law of motion?
Pronunciation: [fˈɜːst lˈɔː ɒv mˈə͡ʊʃən] (IPA) 
There are a few different synonyms that can be used to describe the first law of motion, which is the principle that 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 unbalanced force. Some phrases that can be used to describe this law include the law of inertia, Newton's first law, and the principle of inertia. These all describe the same fundamental concept, which is that objects tend to continue doing what they are already doing, unless something comes along to change that. This law underlies many other principles and theories in physics and engineering.
