Hello

Can someone explain to me what is inertial forces, and why is it that its attributes are the same as weight?

Weight is caused by gravitational field, which field causes inertial forces?

Regards

May I suggest lookng on Understanding Physics of Inertial Forces: Force Effects Caused by Inertia and Accelerating Reference Frames | Suite101.com

I had a look at those articles but could get my answer.

I don't know if my answer is good, but I'll give it a try, since nobody else is trying to answer your question.

Inertia arise from the mass of an object. The more massive (heavy) an object is, the more inertia it has. Inertia is the opposition of an object to movement. For example, you have a tennis ball flying towards you. It is indeed rather easy to stop it with bare hands. However, if a golf ball was flying towards you with the same speed (a little smaller, but more massive), it will be very difficult to stop it, hence, oppose its motion.

Inertial forces are in fact the effects caused by inertia, when an object is in or on something that is accelerating. Have you ever felt some 'force' pushing on you when you are in a car which is accelerating, that push is towards the back. This is because of your inertia, and the force you experience is the inertial force. The same thing, but in the opposite direction happens when the car deccelerates.

First of all thanks for your reply.

I do understand Inertial forces, my question really is why its attribute is the same as that of weight?

Is it because weight which is caused by gravitational force is proportional to mass, while inertial forces are also proportional to mass? (Not that this answers my question fully but one aspect of it.)

Cheers!

Yes, you have it right. Gravitational forces are proportional to mass - as long as the value of acceleration due to gravity is constant. If you travel to another planet, or the moon, where gravity is different, your weight will be different (for example - on the moon you would weigh 1/6 of what you weigh on earth). But your mass remains constant regardless of the strength of the gravitational field.

I'm not so sure you understand inertia. Be very certain that you understand that inertia is not a force and there are no real inertial "forces". As the article notes, what we call inertial forces are only " effects caused by an object's inertia when the object is in or on something that is accelerating".

As Ebaines notes, mass is intrinsic to the object and mass is a measure of an object's inertia.

Where the object is located is irrelevant,





Mass is a measure of an objects inertia.

Inertial force
Centrifugal forces
Centripetal forces*
d'Alemberts force
Fictitious force
Pseudo force
Coriolis force

I do understand these, but what I do not understand is the mechanism behind this.

Inside a spaceship accelerating at 9.8 m/s2, I would feel the same as I feel on earth. Why I cannot tell the difference whether it is my weight caused by gravitational force or it is my inertial force, there should be some way to detect the difference because the mechanism that causes the two 'forces' are different.

Regards
S

In any case... let us consider two cases where you are standing. On earth. The force of gravity is pulling you toward the center of the earth. You feel the force of your feet pressing on the ground (because gravity is pulling you down) and in general your body structure adjusts to the force of gravity.


In a space ship, the ship is accelerating. The floor of the ship is pushing on your feet. But the inertia of your body is resisting and you sense the force of the floor pushing on your feet as the equal and opposite force of your feet pressing against the floor. It feels just like the load on your feet that you would feel in a gravity field.

More generally, loads due to the inertia of your body as the ship accelerates result in loadings to the structure of your body that are the same as experienced in the 1 G gravity field so you sense no difference.

Two different phenomena, but they feel the same.

I did some fact finding about this and have come up with some very interesting facts:

Inertial forces have the same attribute as weight (which is caused by gravitaional force) is because gravitaional force is proportional to mass and it is mass that causes inertial force too. Please correct me if I am wrong here.

I did some more fact finding about mass and discovered mass is caused by higgs field, so I assume it must be the higgs field that causes inetial force as this is what they are trying to find why it takes force to accelerate a body with mass. Please correct me if I am wrong again (I think if higgs field doesn't explain inertial forces then it would be very difficult to understand what it does, because inertial force is the only attribute that mass has, apart from gravity).

1) Inertial force is same as weight can also be called the principle of equivalence, which is regarded as 'remarkable coincidence'.

2) Weight is caused by gravitaional field and the theory of quantum gravity is said to have failed, it runs into non-renormalization trouble.

3) Higgs theory has its own problems, higgs field is said to have its own mass and that it permeats the whole universe, on calculation it is found that the mass of higgs filed alone would exceed the mass of dark energy as calculated by WMAP mission. Furthermore higgs boson is never discovered, so in a nutshell, outside of the higgs theory itself there is no evidense the higgs field exists, the theory is incomplete.

4) Thus gravitaional field which causes weight is incomplete, higgs field that causes inertial forces is also incomplete. And this makes it another remarkable coincidence.

Once you say inertia causes a force you go off the track.

I think you are taking it off track, I am talking about principle of equivalence, this is regarded as remarkable coincidence.

Inertial mass or mass is caused by higgs field, an incomplete theory
Gravitatinal mass is caused by gravitational field, another incomplete theory.

Why both the theories are incomplete, that sounds like a remarkable coincidence about another remarkable coincidence.