Mechanical Energy and Non-Conservative Work
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RELATE wiki by David E. Pritchard is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License |
Description
[Model Hierarchy]
Page Contents |
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Assumed Knowledge
Prior Models
Vocabulary
System.
Internal Forces
External Forces
Conservative Forces
Non-conservative forces
Model Specification
This model is applicable to a system of one or more [point particles/point particle] or [rigid objects] subject to the influence of external [non-conservative forces]. (..implications of internal-conservative forces)
System Structure
Internal Constituents: One or more Point particles or [rigid objects].
Environment: External forces that do non-conservative work because these are one of the forces that can change the mechamical energy. (The internal non - conservative forces also change the mechanical energy).
Descriptors
Object Variables: Mass or moment of inertia for each object about a given axis of rotation, (mj) or (IQ), (?the spring constant of applicable)
State Variables: Kinetic energy for each element of the system and the potential energy of the system. (? Or alternatively, linear speed or angular speed, (vj) or (_wj) for each object inside the system and the position of each of the objects in the system).
Interaction Variables: External forces (Fext,k) or, alternately, the work done by the external forces on the system (here the internal non-conservative interactions are important- do we define them here?).
Laws of Interaction
\begin
$ $\end
Laws of Change
\begin
$E_
= \vec
_
+ W_
^
$\end
where Wexti,f is the work done by the all the external forces on the system between the initial state defined by Ei and the final state defined by Ef and is give by
\begin
$ W_
^
= \int_
^
\sum \vec
^
. d\vec_r $ \end