h2. Keys to Applicability {table:align=right|cellspacing=0|cellpadding=1|border=1|frame=box|width=40%}{tr}{td:align=center|bgcolor=#F2F2F2}*[Model Hierarchy]*{td}{tr}{tr}{td}{pagetree:root=Model Hierarchy|reverse=true}{td}{tr}{table} {excerpt}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 a subclass of the model [Momentum and Impulse] defined by the constraint _dm/dt_ = 0.{excerpt} ---- ||Page Contents|| |{toc:style=none|indent=10px}| ---- h2. Assumptions and Limitations h4. Prior Models * [One-Dimensional Motion with Constant Acceleration|1-D Motion (Constant Acceleration)]. h4. Vocabulary * [Newton's First Law] * [Newton's Second Law] * [Newton's Third Law] * [mass] * [acceleration] * [force] ---- h2. Model Specification h4. System Schema *[Constituents|system constituent]:* [Point particle|point particle]. *[Interactions|interaction]:* External influences must be understood sufficiently to draw a [free body diagram] for the system. h4. Descriptors *[Object Variables|object variable]:* {latex}\begin{large}\[m\]\end{large}{latex}. *[State Variables|state variable]:* None. *[Interaction Variables|interaction variable]:* {latex}\begin{large}\[\vec{F}^{\rm ext}_{i}\]\end{large}{latex} (i = 1,2,...,n where n is the number of external forces acting), {latex}\begin{large}\[\vec{a}\]\end{large}{latex}. ---- h2. Model Equations h4. Mathematical Statement of the Model {latex}\begin{large} \[ \sum_{i} \vec{F}^{\rm ext}_{i} = m\vec{a} \] \end{large} {latex} {note}As with all vector equations, this Law of Interaction should really be understood as three simultaneous equations:\\ {latex}\begin{large}\[ \sum_{i} F^{\rm ext}_{i,x} = ma_{x}\] \[ \sum_{i} F^{\rm ext}_{i,y} = ma_{y}\] \[\sum_{i} F^{\rm ext}_{i,z} = ma_{z}\]\end{large}{latex}{note} ---- h2. Relevant Examples {contentbylabel:dynamics,example_problem|showSpace=false|showLabels=false|maxResults=50|operator=AND} ---- {search-box} \\ \\ | !copyright and waiver^copyrightnotice.png! | RELATE wiki by David E. Pritchard is licensed under a [Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License|http://creativecommons.org/licenses/by-nc-sa/3.0/us/]. | \\ |