# I Possible Error in Goldstein's Classical Mechanics 3rd Edition

#### Laudator

1st page of Chapter 7, p.276, very last line, p=p'. I get that in Newtonian mechanics, the forces, times and masses are the same in two different inertial reference frames, but shouldn't the momenta measured be different?

Related Classical Physics News on Phys.org

#### Orodruin

Staff Emeritus
Homework Helper
Gold Member
2018 Award
Can you provide more context? Everybody is not sitting with a copy of the 3rd edition at a handy distance.

#### Orodruin

Staff Emeritus
Homework Helper
Gold Member
2018 Award
Velocity is different and so momentum is different. $\vec p’ = \vec p - m\vec v$, where $\vec v$ is the relative velocity between the inertial frames.

#### andresB

I think that what the authors wanted to say is that Newton equation remains true if you change the original terms by the transformed ones. Though, doing a literal reading that last equation is wrong.

#### Filip Larsen

Gold Member
I have found an (unofficial) errata sheet for the 2nd edition to go with my copy of the textbook, but apart from someone in American Journal of Physics in 2003 pointing out the physical impossibility implied by the front cover figure, I have not been able to find errata for 3rd edition.

From the snapshot above it appears that 3rd edition has significant changes that probably will make it an arduous task to use 2nd edition errata. For what it is worth, it also appears to me that equation (7.2) and its accompanying text, as show in the snapshot above, is new in 3rd edition. The Galilean transformation in equation (7.1) in 3rd edition is equation (7.8) in 2nd edition and it here derived as the "small velocity limit" of the Lorentz transformation.

#### DrClaude

Mentor
There is an erratum available:

$$\mathbf{F}' = \frac{d}{dt'} \mathbf{p}'$$
as @andresB pointed out above.

#### vanhees71

Gold Member
The newer editions of Goldstein have to be taken with a grain of salt. There are serious conceptual errors in it (concerning non-holonomous constraints, treated wrongly as vasconomic dynamics).

#### nasu

What is the meaning of "vasconomic"? Google did not give any hit for vasconomic dynamics.

#### vanhees71

Gold Member
Sorry, the right spelling is "vakonomic".

#### nasu

Thank you. Google did not suggest it when I was looking for vasconomic. :) It does not know everything. Yet.

"Possible Error in Goldstein's Classical Mechanics 3rd Edition"

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving