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[NOTES/CM-08009] Centrifugal force --- Effect of Earth's RotationNode id: 6222pageThe effect of Coriolis force on the force acting on a body on the earth is computed at the poles, equator and at a general point. he banking of railway tracks and of roads is briefly discussed. |
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24-06-19 16:06:55 |
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[NOTES/CM-08015] Rotations in Three DimensionsNode id: 6301pageThe set of all rotations that can be implemented physically in three dimensions form a group. These most important and frequently used rotations are the rotations which can be implemented physically. These rotations, do not change the handedness of the coordinate axes and are called proper rotations. The improper rotations take left handed systems to right handed systems, or vice versa. The statement of Euler's theorem about rotations is given. $\newcommand{\Prime}{{^\prime}}$ |
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24-06-18 05:06:55 |
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[NOTES/CM-08013] Rotation of a Vector about \(X_3\)- AxisNode id: 6230pageWe derive the transformation rules for a rotation about \(X_3\)- axis. The concept of active and passive rotations is briefly explained.$\newcommand{\Label}[1]{\label{#1}}, \newcommand{\Prime}{^\prime}\newcommand{\eqRef}[1]{\eqref{#1}}$ |
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24-06-17 22:06:43 |
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[NOTES/CM-08011] Rotations about a fixed axisNode id: 6224pageRotations about a fixed axis form a one parameter subgroup of rotations. |
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24-06-17 22:06:47 |
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[NOTES/CM-08006] Axis Angle Parametrization of Rotation Matrix Node id: 6218page$\newcommand{\Prime}{{^\prime}}\newcommand{\U}[1]{\underline{\sf #1}}$
A closed form expression for rotation matrix is derived for rotations about an axis by a specified angle \(\theta\).
\begin{equation} R_{\hat{n}}(\theta)=\widehat {Id}-\sin (\theta) (\hat{n}\cdot \vec{I})+(1-\cos \theta)(\hat{n}\cdot\vec{I})^{2} \end{equation}Here \(\widehat{Id} \) is the identity matrix. and \(\vec{I}=(I_1,I_2,I_3)\) is given by \begin{equation} I_1=\left[\begin{array}{clc} 0 &0 &0\\ 0 &0 &-1\\ 0 &1 &0 \end{array}\right],I_2=\left[\begin{array}{clc} 0 &0 &1\\ 0 &0 &0\\ -1 &0 &0 \end{array}\right],I_3=\left[\begin{array}{clc} 0 &-1 &0\\ 1 &0 &-1\\ 0 &1 &0 \end{array}\right] \end{equation}.
Also the components of the position vector a point transform a
\begin{equation} {\vec{x}}\Prime=(\hat{n}\cdot{\vec{x}})\hat{n}+\cos\theta\big(\vec{x}-(\vec{x}\cdot\vec{n})\hat{n}\big)-\sin\theta (\hat{n}\times \vec{x})\end{equation}
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24-06-17 22:06:34 |
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[NOTES/CM-08004] Equation of Motion in Non Inertial FramesNode id: 6220page$\newcommand{\U}[1]{\underline{\sf #1}}\newcommand{\pp}[2][]{\frac{\partial #1}{\partial #2}}\newcommand{\dd}[2][]{\frac{d#1}{d#2}} \newcommand{\Label}[1]{\label{#1}}$
We derive an expression for Lagrangian for motion of a charged particle in a rotating frame, It is shown that the equation of motion can be written as
\begin{eqnarray} m\ddot{\vec{x}}=\vec{F_{e}}-2m\vec{\omega}\times{\dot{\vec{x}}}-m\vec{\omega} \times(\vec{\omega}\times\vec{x}) \end{eqnarray} where \(\vec {F}_e\) is the external force. As seen from the rotating frame, the particle moves as if it is under additional forces
- $-2m\vec{\omega}\times{\dot{\vec{x}}}$ is called Coriolis force
- $-m\vec{\omega}\times(\vec{\omega}\times\vec{x})$ is known as centrifugal force
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24-06-17 20:06:56 |
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[NOTES/CM-08014] Active and Passive RotationsNode id: 6229pageThe active and passive view of rotations are defined and relationship between them is described.
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24-06-17 19:06:18 |
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[NOTES/CM-08001] The Group of Special Orthogonal Matrices in \(N\) DimensionsNode id: 6232page$\newcommand{\Label}[1]{\label{#1}}\newcommand{\eqRef}[1]{\eqref{#1}}\newcommand{\U}[1]{\underline{\sf #1}}$
All orthogonal all \(N\times N\) orthogonal matrices form a group called \(O(N)\). The set of all orthogonal matrices with unit determinant form a subgroup \(SO(N)\) . The group of all proper rotations coincides with \(SO(3)\). |
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24-06-16 15:06:35 |
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[NOTES/CM-08010] Motion in Frames with Linear AccelerationNode id: 6223page$\newcommand{\Prime}{{^\prime}}\newcommand{\pp}[2][]{\frac{\partial#1}{\partial #2}} \newcommand{\PP}[2][]{\frac{\partial^2#1}{\partial #2^2}} \newcommand{\dd}[2][]{\frac{d#1}{d #2}}\newcommand{\DD}[2][]{\frac{d^2#1}{d #2^2}}$
The equations of motion in a linearly accelerated are are derived and an expression for pseudo force is obtained. |
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24-05-09 12:05:47 |
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[NOTES/CM-08003] Euler AnglesNode id: 6216page$\newcommand{\Prime}{^{\prime}}$
Euler angles are an important ways of parametrization of rotations. The definition of Euler angles and and expression of the rotation matrix in terms of the Euler angles are given. |
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24-05-09 12:05:39 |
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[NOTES/CM-08008] Proper Rotations and $SO(3)$Node id: 6219page$\newcommand{\Prime}{{^\prime}}\newcommand{\Label}[1]{\label{#1}}$
The definition and properties of proper rotations are presented. |
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24-05-09 10:05:41 |
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[NOTES/CM-08012] Matrices for Rotations about Coordinate AxesNode id: 6225pageThe rotation matrices for rotations about the three axes are listed. |
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24-05-03 08:05:13 |
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[NOTES/CM-08002] An explicit form of rotation matrixNode id: 6214pageFor two sets of coordinate axe \(K\) and \(K^\prime\) having common origin, an explicit form of the rotation matrix connecting them is obtained in terms of direction cosines. |
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24-05-03 04:05:37 |
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[NOTES/CM-08005] Finite Rotations of Vectors about an Arbitrary AxisNode id: 6217page$\newcommand{\Prime}{{^\prime}}$
Using geometrical arguments, we will derive the result \begin{equation}\vec{A}^\prime = \vec{A} - (\hat{n}\times\vec{A})\, \sin\alpha + \hat{n}\times (\hat{n}\times\vec{A})\, (1-\cos\alpha ) \end{equation}between components of vectors related by a rotation by and angle \(\theta\) about an axis \(\hat n\). |
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24-05-02 20:05:20 |
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