Skip to main content

All Questions

2 votes
1 answer
89 views

Time derivative of a "general" vector $\vec A$ in an accelerating frame: what about e.g. velocity $\vec v$?

According to Morin "Classical Mechanics" (Section 10.1, page 459), the derivative of a general vector $\vec A$ in an accelerating frame may be given as $$\frac{d\vec A}{dt}=\frac{\delta \vec ...
klonedrekt's user avatar
0 votes
2 answers
119 views

Question about velocities in different reference frames

Suppose $\hat{x^{'}}, \hat{y^{'}}, \hat{z^{'}} $ are the unit vectors of an inertial frame and $\hat{x}, \hat{y}, \hat{z} $ are the unit vectors of a frame which maybe accelerating, rotating, whatever....
Neeladri Reddy's user avatar
0 votes
1 answer
68 views

Doubt in fictitious forces chapter in Morin

The question is this - I know 2 is what the non-inertial frame measures, but isn't $\frac{d\mathbf{A}}{dt}$ the real thing, the physical thing? And you can write that too in terms of the unit vectors ...
Neeladri Reddy's user avatar
0 votes
1 answer
91 views

On the isomorphism between directed line segments and "abstract vectors" (Gregory Classical Mechanics)

I have just begun reading Gregory's Classical Mechanics and, amazingly, he has blown my mind in the first chapter discussing nothing more than measly old vector algebra. Fascinating that Gregory was ...
EE18's user avatar
  • 1,095
2 votes
1 answer
258 views

Having trouble deriving the exact form of the Kinematic Transport Theorem

The Kinematic transport theorem is a very basic theorem relating time derivatives of vectors between a non rotating frame and another one that's rotating with respect to it with a uniform angular ...
Amit's user avatar
  • 1,417
1 vote
1 answer
91 views

How to define differentiation of a time-dependent vectors with respect to a specific reference frame in a coordinate-free manner?

It is usual in classical mechanics to introduce the derivative of a time-dependent vector with respect to a reference frame. This is accomplished through the use of a basis that is fixed with respect ...
jvf's user avatar
  • 245
1 vote
2 answers
334 views

Frames of references and coordinate systems

In linear algebra, a vector can be represented by different bases. However, this is merely a different representation of the same entity; i.e. $\vec x = x\hat\imath + y\hat\jmath + z\hat k = x'\hat\...
dk30's user avatar
  • 27
5 votes
3 answers
437 views

Passive transformation, pseudo vectors and cross product

Let's consider the passive transformation i.e. inversion only of the basis vectors (coordinate axes) and all other vectors remaining the same and check if the cross product is a pseudo vector. After ...
Kashmiri's user avatar
  • 1,260
5 votes
7 answers
2k views

Why can basis vectors change direction?

I thought that basis vectors were of magnitude one and located at the origin and were each linearly independent, so how in things like polar coordinates can the basis vectors be moving?
CatsOnAir's user avatar
  • 139
0 votes
1 answer
57 views

Dummy variables and Galilean Invariance

I've faced a small doubt, and I was hoping someone could verify this for me. According to Galilean transformation, consider $2$ frames - $S_1$ and $S_2$ moving relative to each other. $S_1$ is at rest,...
Nakshatra Gangopadhay's user avatar
1 vote
2 answers
185 views

Resolution of vectors along different directions

I have a small doubt regarding the resolution of forces and vectors. Suppose, we have our standard cartesian coordinate system, with unit vectors $\hat{i}$ and $\hat{j}$. Now we have defined polar ...
Nakshatra Gangopadhay's user avatar
0 votes
2 answers
154 views

Generalized coordinates as components

Why we cannot express Generalized coordinates as a vector like we do with Cartesian coordinates $x$ , $y$ ,$z$ ?
Apar Sharma's user avatar
8 votes
3 answers
735 views

In a general physical sense, is the position of a particle really a vector?

Is it consistent to define the position of a particle in some frame as a vector or is just an informal representation? Velocity and acceleration can be added up and multiplied by real numbers and ...
Генивалдо's user avatar
4 votes
5 answers
697 views

Why we use vectors?

When we say that the position of an object is +5m on x axis why we need to use vectors? I mean could we don't use vectors and just say +5m on x or y or z axis instead of writing 5*unit vector either $...
Antonios Sarikas's user avatar