Keys to Applicability
[Model Hierarchy]
This model is applicable to a point particle (or to a system of objects treated as a point particle located at the system's center of mass) when the external forces are known or needed. It is often useful in combination with other models that require quantitative knowledge of forces for their application. It is a subclass of the model [Momentum and Impulse] defined by the constraint dm/dt = 0.
Page Contents |
|---|
Assumptions and Limitations
Prior Models
Vocabulary
Model Specification
System Schema
Constituents: Point particle, or a system of constant mass that is treated as a point particle located at the system's center of mass.
Interactions: External forces must be understood sufficiently to draw a free body diagram for the system. Internal forces will always cancel from the equations of Newton's 2nd Law for the system and can be neglected.
Descriptors
[State Variables]: Mass (m) (must be constant in this model).
[Interaction Variables]: External forces Fextk (k = 1,2,...,N where N is the number of external forces acting), acceleration (a).
Model Equations
Mathematical Statement of the Model
\begin
[ \sum_
\vec
^
_
= m\vec
] \end
As with all vector equations, this Law of Interaction should really be understood as three simultaneous equations:
\begin
[ \sum_
F^
_
= ma_
]
[ \sum_
F^
_
= ma_
]
[\sum_
F^
_
= ma_
]\end
Relevant Examples
null |
RELATE wiki by David E. Pritchard is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License |
