10 Examples of Inertia

Inertia

We have all noticed at some point that if we ride standing on the bus and stop suddenly, our body tends “to continue traveling ”, which forces us to quickly take hold of a firm element inside the bus so as not to fall down.

This happens because bodies tend to maintain their state, of rest or of movement, unless they are subjected to the action of a force. To this physics phenomenon he recognizes it as "inertia."

The inertia It is the resistance that matter opposes to modify its state of rest or movement, and that state is only modified if a force acts on them. It is said that a body has greater inertia the greater resistance it opposes to modify its state.

Types of inertia

Physics distinguishes between mechanical inertia and thermal inertia:

Newton's first law

The idea of ​​inertia has been embodied in Newton's first law or law of inertia, according to which if a body is not subject to the action of forces, it will maintain at all times its speed in magnitude and in direction.

However, it is interesting to note that before Newton, the scientist Galileo Galilei had already raised this concept by confronting the Aristotelian point of view in his work 

Dialogues on the two great systems of the world, Ptolemaic and Copernican, dating from 1632.

There he says (in the mouth of one of his characters) that if a body were to slide along a smooth and perfectly polished plane, it would maintain its movement ad infinitum. But if this body were to slide on an inclined surface, it would suffer the action of a force that could cause it to accelerate or decelerate (depending on the direction of the inclination).

So Galileo already envisioned that the natural state of objects is not exclusively that of rest, but also that of a rectilinear and uniform movement, as long as there are no other forces acting.

Associated with this physical concept, when describing human behaviors, the other meaning of the term inertia appears, which is applied to those cases in which people do not They do nothing about something out of laziness, adherence to routine, comfort, or simply to let themselves be as they are, which is often the easiest thing to do.

Examples of inertia in everyday life

Many everyday situations account for the physical phenomenon of inertia:

1. Inertial seat belts. They only lock if the body continues to move when there is a sudden stop.
2. Washing machine with spin. The washing machine drum has small holes so that when spinning to spin the clothes, the drops of water that have a certain speed and direction to continue in its movement and pass through the holes. It is said then that the inertia of the drops, the state of movement that they possess, helps to remove the water from the clothes.
3. Catching the ball in soccer. If an archer does not stop with his arms the ball applied by the striker of the opposing team, there will be a goal. The ball in motion, due to its inertia, will continue to travel into the goal unless a force, that of the goalkeeper's hands in this case, prevents it.
4. Pedaling by bicycle. We can advance with our bicycle a few meters after having pedaled and stop doing it, the inertia makes us advance until the friction or the friction exceeds it, then the bicycle stops.
5. Hard-boiled egg test. If we have an egg in the refrigerator and we do not know if it is raw or cooked, we support it on the counter, we do it turn carefully and with a finger we try to stop it: the hard-boiled egg will stop immediately because its content it is solid and it forms a whole with the shell, so that if the shell is stopped, the interior also stops. However, if the egg is raw, the liquid the inside does not stop immediately along with the shell, but will continue to move for a while longer due to inertia.
6. Remove a tablecloth and leave what is above resting on the table, in the same place. A classic magic trick based on inertia; to get it right you have to pull the tablecloth down and the object should be rather light. The object resting on the tablecloth opposes the change in its state of movement, it tends to remain still.
7. The shots with effect in billiards or pool. When trying to achieve the caroms, taking advantage of the inertia of the balls.