Define newtons first law of motion?

Answer 1

a body remains at rest or in motion with a constant velocity unless acted upon by external force.

Answer 2

If you are referring to Newtons laws of motion the laws are as follows,

1. First law: Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force. This means that in the absence of a non-zero net force, the center of mass of a body either remains at rest, or moves at a constant speed in a straight line.
2. Second law: A body of mass m subject to a force F undergoes an acceleration a that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma. Alternatively, the total force applied on a body is equal to the time derivative of linear momentum of the body.
3. Third law: The mutual forces of action and reaction between two bodies are equal, opposite and collinear. This means that whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction. This law is sometimes referred to as the action-reaction law, with F called the "action" and −F the "reaction". The action and the reaction are simultaneous.

Answer 3

Every body continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by an external source, impressed upon it.

Answer 4

an object in motion will stay in motion unless a force is acted upon it, and an object at rest will stay in rest unless a force is acted upon it.

Answer 5

Newtons first law of motion states that an object in motion will stay in motion and an object at rest will say at rest.

Answer 6

an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction, unless acted upon by an unbalanced force