Here's why:
* Newton's First Law (Law of Inertia) describes how objects at rest stay at rest, and objects in motion stay in motion at a constant velocity unless acted upon by a net force. It doesn't directly define force.
* Newton's Second Law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This is expressed mathematically as: F = ma
* F is the net force
* m is the mass of the object
* a is the acceleration of the object.
Therefore, Newton's Second Law is the key to measuring force. By knowing the mass of an object and its acceleration, you can calculate the net force acting upon it.
