• Converging forces

    From Luigi Fortunati@fortunati.luigi@gmail.com to sci.physics.research on Sun Apr 27 22:19:48 2025
    From Newsgroup: sci.physics.research

    The corpuscle P is stationary at the point x_P=0, while the bodies A
    and B approach at the same velocity from the left and right, arriving simultaneously on the corpuscle P, as can be seen in the animation https://www.geogebra.org/classic/fyymjr9s

    During the collision, the crushing of the spherical corpuscle P always
    occurs (regardless of the mass of the two bodies A and B) because the
    forces F1 and F2 are convergent.

    Instead, the acceleration of the corpuscle P may or may not occur,
    because P, after the collision, can start moving to the right or to the
    left (varying its speed from zero to +v or -v) or it can remain
    stationary in its initial place x_P=0, leaving its zero speed
    unchanged.

    What conditions must be met for the corpuscle P to accelerate to one
    side or the other and what conditions for it to remain stationary in
    its place?

    Luigi Fortunati

    [[Mod. note -- If (and only if) A and B have the same mass, then the
    system is left-right symmetric, so P will remain stationary.
    -- jt]]
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  • From Luigi Fortunati@fortunati.luigi@gmail.com to sci.physics.research on Sun Apr 27 22:23:11 2025
    From Newsgroup: sci.physics.research

    [[Mod. note -- I'm sorry, I mistakenly posted an earlier draft of this
    article. The mistake was mine, not the author's. I believe this is the correct version.
    -- jt]]

    The small body P is at rest at the point x_P=0, while the bodies A and
    B approach at the same speed from the left and right, arriving at P at
    the same time, as shown in the animation https://www.geogebra.org/classic/ptkfwqh5

    During the collision, the crushing of the tiny body P is always there (regardless of the mass of the two bodies A and B) because the forces
    F1 and F2 are convergent.

    Instead, the acceleration of P may or may not be there because, after
    the collision, P can start moving to the right or to the left (changing
    its speed from zero to +v or -v) or it can remain at its initial place
    x_P=0, leaving its zero speed unchanged.

    What conditions must be met for P to accelerate to one side or the
    other and what conditions for it to remain at rest in its place?

    If the small body P is not there and the points A and B collide
    directly with each other, do the forces F1 and F2 stop being
    convergent?

    Luigi Fortunati

    [[Mod. note -- We are given that A and B have the same speed. So, if
    (and only if) A and B have the same mass, then the system is left-right symmetric, so P will remain stationary.
    -- jt]]
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  • From Luigi Fortunati@fortunati.luigi@gmail.com to sci.physics.research on Wed Apr 30 07:04:27 2025
    From Newsgroup: sci.physics.research

    Luigi Fortunati il 27/04/2025 17:23:11 ha scritto:
    The small body P is at rest at the point x_P=0, while the bodies A and
    B approach at the same speed from the left and right, arriving at P at
    the same time, as shown in the animation https://www.geogebra.org/classic/fyymjr9s

    During the collision, the crushing of the tiny body P is always there (regardless of the mass of the two bodies A and B) because the forces
    F1 and F2 are convergent.

    Instead, the acceleration of P may or may not be there because, after
    the collision, P can start moving to the right or to the left (changing
    its speed from zero to +v or -v) or it can remain at its initial place x_P=0, leaving its zero speed unchanged.

    What conditions must be met for P to accelerate to one side or the
    other and what conditions for it to remain at rest in its place?

    If the small body P is not there and the points A and B collide
    directly with each other, do the forces F1 and F2 stop being
    convergent?

    Luigi Fortunati

    [[Mod. note -- We are given that A and B have the same speed. So, if
    (and only if) A and B have the same mass, then the system is left-right symmetric, so P will remain stationary.
    -- jt]]

    If A and B have the same mass, will only P remain stationary or will
    the entire system A+P+B remain stationary?

    Are the internal forces of the system A+P+B (F1 and F2) in equilibrium
    only if A and B have the same mass or are they also in equilibrium when
    their masses are different?

    Luigi Fortunati
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  • From Luigi Fortunati@fortunati.luigi@gmail.com to sci.physics.research on Sun May 4 12:11:10 2025
    From Newsgroup: sci.physics.research

    Luigi Fortunati il 30/04/2025 09:04:27 ha scritto:
    The small body P is at rest at the point x_P=0, while the bodies A and
    B approach at the same speed from the left and right, arriving at P at
    the same time, as shown in the animation
    https://www.geogebra.org/classic/fyymjr9s

    During the collision, the crushing of the tiny body P is always there
    (regardless of the mass of the two bodies A and B) because the forces
    F1 and F2 are convergent.

    Instead, the acceleration of P may or may not be there because, after
    the collision, P can start moving to the right or to the left (changing
    its speed from zero to +v or -v) or it can remain at its initial place
    x_P=0, leaving its zero speed unchanged.

    What conditions must be met for P to accelerate to one side or the
    other and what conditions for it to remain at rest in its place?

    If the small body P is not there and the points A and B collide
    directly with each other, do the forces F1 and F2 stop being
    convergent?

    Luigi Fortunati

    [[Mod. note -- We are given that A and B have the same speed. So, if
    (and only if) A and B have the same mass, then the system is left-right
    symmetric, so P will remain stationary.
    -- jt]]

    To the left of P there is only the force of the action to the right of
    body A, to the right of P there is only the force of the reaction to
    the left of body B.

    On the tiny body P the forces of the action of A and the reaction of B *converge*.

    These two converging and opposite forces are F1 and F2.

    If F1 and F2 were ALWAYS equal and opposite (as Newton's third law
    states), body P should never start moving, should never accelerate and
    should always remain stationary at x_P=0.

    Instead, you have just stated (correctly) that P remains stationary if
    (and only if) the masses of the two bodies A and B are equal and NOT
    when they are different.

    Therefore Newton's third law is wrong.

    The forward action of the Newton's horse on the rope and the backward
    reaction of the stone on the rope are equal when the rope is
    stationary, they are also equal when the rope moves with uniform motion
    but they are NOT equal when the rope accelerates and, therefore, the
    third law is wrong.

    In tug-of-war, the leftward action of team A equals the rightward
    reaction of team B only when the rope is stationary and when it is
    moving uniformly but not when the rope is accelerating.

    How many more ways do I have to prove that Newton's third law is wrong?

    Luigi Fortunati.
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