## Is Inertial Force not a Real Force ?

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
Inertial force caused by external force (except gravity) or by rotation can be calculable with internal force. Inertial force caused in a body falling vertically in a stationary fluid can be calculable from gravity and fluid resistance (of every moment). In the same gravitational field, in free fall, fluid resistance is zero.

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
From the roof of a passenger car, a body is hung. The passenger car increases acceleration to the right and the string hanging the body now shows 45 degrees angle. It means that gravity and inertial force are equalized (inertial force is caused by "aether resistance" that resists acceleration). The two can be actions and the tension of the string can be reaction. Inertial force is a real force (as an action on the potential energy also).

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
On the floor of a passenger car, the same five bodies form a line. Between the first body and the right wall, and between five bodies are joined with strings. Now, the passenger car starts a uniform accelerated motion to the right. Friction of the floor is supposed to be zero and mass of strings to be zero also. Tension of the first string will be 5ma and the last string will be 1ma (when acceleration is double, 10ma and 2ma). It will be the same to every observer. Inertial force is a real force.

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
In a uniform accelerated motion (ideal), both sides of F = ma continue constantly. Acceleration a continues constantly also. Namely, action and reaction are equal and the body is accelerated. An equal sign assures that inertial force is a real force.

P.S. How valid is F = ma in actual situation ? It seems not to be certain. The certain thing is that inertial force is ma always and is a real force.

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
On a disk rotating horizontally, centrifugal force is acting. Our image of centrifugal force is a force acting on a line that heads outward from the center. But probably, on the disk (at every point), the same two forces (drawing) will be acting from the both sides in the arc direction. This force (caused by centrifugal force) is an inertial force and is a real force also (just like centrifugal force).

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
In rotational motion, inertial force (centrifugal force) will be measurable easily by internal force. In non-gravitational field, inertial force will be measurable reliably by internal force (On the earth surface also. But the internal force is horizontal direction only). Inertial force is a real force.

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
In a formula F = ma, on F (force), two interpretations (force as output and force as input) seems to be possible. On force output, the formula (ma = F) stands up always. But, how about force input ?

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
Inertial force is considered to be fictitious force. About its reason, a web site says that if the external force and inertial force are the same, a body cannot accelerate. Is it a common view ? This view is incompatible with a formula F = ma. Now, a force F is acting on a body. Whether the body accelerates or not, action and reaction will be the same. Formula F = ma will be F = ma + X (case ma is zero and case X is zero)

In a formula F = ma, if F is an invariant (m will be so also), term a will be an invariant also. Aether frame will be a real existence.

Anonymous
Anonymous
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
True!

nakayama
nakayama
1) In outer space, force F pushes a body through a spring (F = ma). A force F that pushes buck the spring (inertial force) will be a real force.
2) In a body accelerated by external force, inertial force will occur (in case of gravity, it is not clear). Inertial force will be a real force.
3) Centrifugal force will be a real force.
4) On a body accelerated in a fluid, a normal force and inertial force will occur. The two will be real forces.
Acceleration is indicated by accelerometer. Namely, acceleration cannot be relative (on rotating motion, it is more evident).