Mechanics

# Brief history of the law of inertia

Newton, from the contributions of Aristotle and Galilei (pictured), formulated the law of inertia

Before we begin our study about movement, let’s analyze the following question: is the action of a force necessary to maintain a movement ?

In situations where it is necessary to move an object (such as a table, chair, sofa, etc.), we have to make a muscular effort to move these objects. In physics, the idea of ​​effort is linked to the concept of force.

For example, a force must be applied to a table to make it move. This can be done by dragging it across the room. But we realize that in order for the movement not to cease, the force must be applied throughout the movement, because if we stop exerting such a force, we will see that the table ceases its movement.

When we run, the same thing happens. To maintain our speed, we need the muscular strength of our legs at all times. If we stop pushing the ground, it stops pushing us and so we stop moving. Many situations like these suggest that the continuous application of force is necessary to keep an object in motion.

According to the philosopher Aristotle, when the force stops acting on a body (object), it immediately returns to its initial state, that is, to rest. And do you agree with the statement of the philosopher Aristotle? If you don’t agree, can you think of an example of an object in motion that remains that way after the force that caused it to move has ended?

You are running a lot when, suddenly, you come across a friend, who, walking distractedly towards you, stops right in front of you. To avoid the collision, do you just stop pushing with your legs? And when you, playing pool, hit the ball, does it stop immediately after contact with the cue or does it keep moving for some time? Think of other similar situations.

We can say that a long time passed before it was admitted that there could be motion even without a force acting on the object. It was Galileo Galilei who, through several experiments, contributed decisively to refute the view that the philosopher Aristotle presented about movement. However, it was Isaac Newton who, based on Galileo’s idealizations, formulated the Principle of Inertia, which, in his honor, we know today as Newton’s First Law.