What is Inertial: Definition and 496 Discussions

In classical physics and special relativity, an inertial frame of reference is a frame of reference that is not undergoing acceleration. In an inertial frame of reference, a physical object with zero net force acting on it moves with a constant velocity (which might be zero)—or, equivalently, it is a frame of reference in which Newton's first law of motion holds. An inertial frame of reference can be defined in analytical terms as a frame of reference that describes time and space homogeneously, isotropically, and in a time-independent manner. Conceptually, the physics of a system in an inertial frame have no causes external to the system. An inertial frame of reference may also be called an inertial reference frame, inertial frame, Galilean reference frame, or inertial space.All inertial frames are in a state of constant, rectilinear motion with respect to one another; an accelerometer moving with any of them would detect zero acceleration. Measurements in one inertial frame can be converted to measurements in another by a simple transformation (the Galilean transformation in Newtonian physics and the Lorentz transformation in special relativity). In general relativity, in any region small enough for the curvature of spacetime and tidal forces to be negligible, one can find a set of inertial frames that approximately describe that region.In a non-inertial reference frame in classical physics and special relativity, the physics of a system vary depending on the acceleration of that frame with respect to an inertial frame, and the usual physical forces must be supplemented by fictitious forces. In contrast, systems in general relativity don't have external causes, because of the principle of geodesic motion. In classical physics, for example, a ball dropped towards the ground does not go exactly straight down because the Earth is rotating, which means the frame of reference of an observer on Earth is not inertial. The physics must account for the Coriolis effect—in this case thought of as a force—to predict the horizontal motion. Another example of such a fictitious force associated with rotating reference frames is the centrifugal effect, or centrifugal force.

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  1. B

    Inertial Reference Frames and Newtons laws

    Homework Statement I am a bit confused about what are inertial reference frames and what is not. The text states: "We define an inertial reference frame as a reference frame in which Newton's laws are valid... Accelerating reference frames are not inertial reference frames...
  2. B

    Fusion via Inertial Confinement

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  3. S

    Inertial load model penetration

    Hi, I have an FEA model where all my parts are bonded contacts (no contact surfaces). I am trying to fix one end of this model and apply inertial load on the other. However the heavy parts are penetrating into the soft ones. How do I avoid this model penetration? Thanks,
  4. B

    Is Poincare Symmetry Fundamental to Relativity as Proposed by Einstein?

    I have heard the following oppinion: Whether a reference frame is inertial is completely determined by whether Newton's laws are applicable for particles moving at low (that is, nonrelativistic) speeds in that reference frame. Do you agree with it?
  5. M

    Breakedown of common sense and inertial ccordinate systems

    1. Let us consider a molecule with almost "zero" binding energy. Why does every textbook declare that it should be a molecule if we accelerate it to some high velocity? Why shouldn't it dissociate at some velocity. 2. Inversly. Consider a molecule moving with some velocity. Why it couldn't...
  6. P

    Why the Galileo transformations are not correct for inertial systems

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  7. P

    Inertial Reference Frames in Train Experiments: Correct Statements

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  8. T

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  9. e2m2a

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  10. Q

    Work-Energy Theorem in Inertial Reference Frames

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  11. R

    Gravitational force = inertial mass

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  12. K

    Is inertial mass of gas the same as its rest mass

    Suppose we have a box at rest that is filled with a uniform gas. We denote the volume by V and the pressure by p. Suppose next that we apply a small force to the box and accelerate it until it has a speed v. The key question is: Is it harder to accelerate the gas because it takes work not only...
  13. J

    Inertial frames and Parity symmetry

    Do you think you could give me some helpful insight to a follow up question from the discussion of defining inertial frames: I'm still having trouble figuring out a good way of incorporating parity violation into my intuition. If it wasn't for experiment showing otherwise, I probably would...
  14. J

    Definition of an Inertial Frame

    Is there some way to define an inertial coordinate system without being cyclical (defining it with terms that require an inertial coordinate system to define)? For example if you refer to straight lines... straight according to what coordinate system? Or if you refer to velocity... that...
  15. B

    Equations relating changes between rotating and inertial frames

    i understand the reason and steps leading to the equation that relates acceleration in the inertial frame to acceleration in the rotating frame i.e. a(I) = a(R) + 2(omega)Xv(R) + (omega)X(omega) X r a(I) = acceleration in inertial frame a(R) = acceleration in rotating frame omega =...
  16. H

    Defining Inertial Reference Frames in General Relativity

    How can you have an inertial reference frame in which a body can remain at rest or move with constant velocity unless you postulate the disappearance of the universe? In the Michelson Morley experiment the Earth is not moving with constant velocity, it is accelerating. So the postulates of...
  17. S

    Why is gravitational mass the same as inertial mass?

    Gravitational mass is the property of objects that determines how they interact via gravity. For example how the Moon rotates around Earth. Inertial mass is an object's property that determines how much the object "resists" acceleration when force is applied to it. And it seems both are...
  18. gabee

    Velocities in rotating and inertial reference frames

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  19. E

    How Large Must a Spark Chamber Be to Qualify as an Inertial Frame?

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  20. W

    Is a rotating system considered inertial?

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  21. L

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  22. L

    Constant Acceleration seen in an inertial frame

    I'm sorry, this topic has certainly already been covered, but I didn't find what I need. I'm trying to compute x(t) in an inertial frame if a rocket has a constant acceleration "a" as measured with accelerometers inside of it. I made these (clearly wrong) computations: In a co-moving...
  23. Y

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  24. J

    Is stoke's number same as inertial impaction parameter?

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  25. L

    About force, mass, Newton's 2nd law and inertial frame

    I was reading a physics textbook. It is stated that force is defined by mass and acceleration (a force of 1N causes a mass of 1kg to accelerate at 1ms^-2). In later part, it is stated that mass is defined by force and acceleration (a mass acted by a force of 1N accelerates at 1ms^-2 is 1kg). As...
  26. E

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  27. O

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  28. K

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  29. M

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  30. G

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  31. Y

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  32. A

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  33. O

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  34. A

    What is an inertial frame of reference ?

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  35. N

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  36. M

    What Forces Influence the Moon in the Sun's Inertial Frame of Reference?

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  37. C

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  38. B

    Length contraction from two inertial frames

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  39. L

    Possible webpage title: Defining Inertial Reference Frames in Classical Physics

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  40. G

    Inertial Frame: Defining Perfection

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  41. Y

    Some Inertial Frames may br more Equivalnet than Others

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  42. I

    Persistence of Relationships in Inertial Frame R

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  43. I

    Inertial Frame R: Persisting Relationships of Particles' Positions & Velocities

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  44. K

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  45. J

    Inertial Frames of Reference: Examining Forces & Acceleration

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  46. A

    Is centripetal force present in inertial and non-inertial frames?

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  47. P

    Gravitational and inertial mass

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  48. L

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  49. J

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  50. S

    Measuring Inertial Mass: Force, Acceleration and Mass

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