Inertial frame

errandir · 2003 September 15th, 18:05

Can y\'all please give me your definitions for inertial frame?

errandir · 2003 September 15th, 18:05

Can y\'all please give me your definitions for inertial frame?

errandir · 2003 September 15th, 18:05

Can y\'all please give me your definitions for inertial frame?

**Fernanda** · 2003 September 15th, 18:14

Inertial Frame of Reference
An inertial frame of reference is any set of coordinates at rest or moving with constant velocity. The laws of physics are unchanged in any one of the inertial frame of reference.

From here

**Fernanda** · 2003 September 15th, 18:14

Inertial Frame of Reference
An inertial frame of reference is any set of coordinates at rest or moving with constant velocity. The laws of physics are unchanged in any one of the inertial frame of reference.

From here

**Fernanda** · 2003 September 15th, 18:14

Inertial Frame of Reference
An inertial frame of reference is any set of coordinates at rest or moving with constant velocity. The laws of physics are unchanged in any one of the inertial frame of reference.

From here

errandir · 2003 September 15th, 19:57

\"At rest or moving with constant velocity\" with respect to what?

errandir · 2003 September 15th, 19:57

\"At rest or moving with constant velocity\" with respect to what?

errandir · 2003 September 15th, 19:57

\"At rest or moving with constant velocity\" with respect to what?

Crisp · 2003 September 16th, 02:42

Hi errandir,

I will also follow this discussion closely to see if it comes out with a different definition than mine in another thread, another forum ;).

I think it\'ll end up the same. As you immediately pointed out, the \"working definition\" of inertial frames has some ambiguity in it. In order to define it, you need another frame of reference, so you can define the velocity of the original frame.

However, the second part of the definition Fernanda gave tries to solve this: you have a rough mechanism to determine if two given frames of reference are inertial (by comparing \"the laws of physics\"), even though I personally have my doubts that this will always settle the debate if you take two frames of reference on the surface of the earth.

So that leaves IMHO only the following definition of inertial frames of reference:

Definition:
1. There exists at least one \"inertial frame of reference\", whatever that might be.
2. Any frame of reference at rest or moving at constant velocity with respect to that frame, is by definition also an inertial frame of reference.

It is a triviality to verify that the laws of physics remain the same under transformation from one frame to the other.

Sort of repeated what I already said, to you errandir, but perhaps some people here have comments on it.

Bye!

Crisp

Crisp · 2003 September 16th, 02:42

Hi errandir,

I will also follow this discussion closely to see if it comes out with a different definition than mine in another thread, another forum ;).

I think it\'ll end up the same. As you immediately pointed out, the \"working definition\" of inertial frames has some ambiguity in it. In order to define it, you need another frame of reference, so you can define the velocity of the original frame.

However, the second part of the definition Fernanda gave tries to solve this: you have a rough mechanism to determine if two given frames of reference are inertial (by comparing \"the laws of physics\"), even though I personally have my doubts that this will always settle the debate if you take two frames of reference on the surface of the earth.

So that leaves IMHO only the following definition of inertial frames of reference:

Definition:
1. There exists at least one \"inertial frame of reference\", whatever that might be.
2. Any frame of reference at rest or moving at constant velocity with respect to that frame, is by definition also an inertial frame of reference.

It is a triviality to verify that the laws of physics remain the same under transformation from one frame to the other.

Sort of repeated what I already said, to you errandir, but perhaps some people here have comments on it.

Bye!

Crisp

1100f · 2003 September 16th, 03:10

Suppose that you have some reference frame where you measure the ratio between the forces that act on any point particle to the acceleration it acquires. If you find that this ratio is constant for each particle, then you say that the reference frame in which you are is an inertial frame. And you call this ratio, which depend on the particle, the particle mass. All reference frames that are moving with constant velocity vector with respect to this one are also called inertial frames.

1100f · 2003 September 16th, 03:10

Suppose that you have some reference frame where you measure the ratio between the forces that act on any point particle to the acceleration it acquires. If you find that this ratio is constant for each particle, then you say that the reference frame in which you are is an inertial frame. And you call this ratio, which depend on the particle, the particle mass. All reference frames that are moving with constant velocity vector with respect to this one are also called inertial frames.

errandir · 2003 September 16th, 10:07

To measure forces is easy, right? You can use a scale (spring displacement).

How does one measure the velocity and acceleration?

errandir · 2003 September 16th, 10:07

To measure forces is easy, right? You can use a scale (spring displacement).

How does one measure the velocity and acceleration?