Inertia
From the Simple English Wikipedia, the free encyclopedia that anyone can change
Inertia is the quality of an object to keep the same velocity unless it is acted upon by an outside force. Inertia is also called Sir Isaac Newton's First Law of Motion. The First Law of Motion says that:
Every body perseveres in its state of being at rest or of moving uniformly straight ahead, except insofar as it is compelled to change its state by forces impressed. [Cohen & Whitman 1999 translation]
This basically means:
Every object stays at rest or stays moving at the same speed unless something makes it change.
