Calculating Average Velocity or Speed

xholonWorkbook.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--Xholon Workbook http://www.primordion.com/Xholon/wb/ (C) Ken Webb Mon Feb 13 2012 19:30:48 GMT-0500 (EST)-->
<XholonWorkbook>

<Notes><![CDATA[
Khan Academy
------------
Title: Calculating Average Velocity or Speed
Description: Example of calculating speed and velocity
Url: http://www.khanacademy.org/video/calculating-average-velocity-or-speed?playlist=Physics
InternalName: calculating-average-velocity-or-speed
YoutubeId: oRKxmXwLvUU
Keywords: Calculating, Average, Velocity, or, Speed

My Notes
--------
displacement = 5 km north
  m meters
  s with a right-directed arrow on top (it's a vector)
time = 1 hour
  s seconds
  t (a scalar)
velocity
  m/s
  v with a right-directed arrow on top
  v = s / t
  speed, rate (a scalar)

dimensional analysis

]]></Notes>

<script implName="lang:python:inline:"><![CDATA[
s = 5.0 * 1000.0         # m
t = 1.0 * 60.0 * 60.0    # s
v = s / t                # m/s
print str(s) + "m / " + str(t) + "s = " + str(v) + "m/s"
# http://ideone.com/43jdb
# result: 5000.0m / 3600.0s = 1.38888888889m/s
]]></script>

<script implName="lang:javascript:inline:"><![CDATA[
  var s = 5.0 * 1000.0;         // m
  var t = 1.0 * 60.0 * 60.0;    // s
  var v = s / t;                // m/s
  print(s + "m / " + t + "s = " + v + "m/s");
  
  // paste this into your browser's address bar (exclude the // comment characters):
  //javascript:(function(s,t){s=s*1000.0;t=t*60.0*60.0;var v=s/t;alert(s+"m/"+t+"s="+v+"m/s");})(5.0,1.0)
]]></script>

<_-.XholonClass>

  <!-- domain objects -->
  <PhysicalSystem/>
  <Car/>
  
  <!-- quantities -->
  <Displacement superClass="Length"/>
  <ChangeInTime superClass="Duration"/>
  <AverageVelocity superClass="Velocity"/>
  
</_-.XholonClass>

<xholonClassDetails>
  <Car>
    <port name="displacement" connector="#xpointer(Displacement)"/>
    <port name="changeInTime" connector="#xpointer(ChangeInTime)"/>
    <port name="averageVelocity" connector="#xpointer(AverageVelocity)"/>
  </Car>
</xholonClassDetails>

<PhysicalSystem>
  <Car>
    <Displacement>5.0 km</Displacement>
    <Attribute_String roleName="direction">north</Attribute_String>
    <ChangeInTime>1.0 h</ChangeInTime> <!-- 1 hour -->
    <AverageVelocity>0.0 m/s</AverageVelocity> <!-- this will be calculated -->
  </Car>
</PhysicalSystem>

<Carbehavior implName="lang:python:inline:"><![CDATA[
# Steps:
# (1) Select the displacement, direction, changeInTime, and averageVelocity nodes
#     in that order.
# (2) Run this script by pasting it into the Car node in the Xholon GUI,
#     or through a Xholon Console on the Car node.
snodes = selectedNodesKey
print snodes
s = snodes[0]    # m
n = snodes[1]    # "north"
t = snodes[2]    # s
v = snodes[3]    # m/s
v.setVal((s.val*1000.0) / (t.val*3600))
print "v = " + str(v.val) + " " + v.unit + " " + n.val_String
]]></Carbehavior>

<Carbehavior implName="lang:javascript:inline:"><![CDATA[
// TODO
//height.incVal(0.02);
//print("JavaScript wants something to do. Height:" + height + "\n");
]]></Carbehavior>

<Carbehavior implName="lang:bsh:inline:"><![CDATA[
// TODO
//height.incVal(0.02);
//System.out.print("Java/Beanshell wants something to do. Height:" + height + "\n");
]]></Carbehavior>

<Carbehavior implName="lang:jruby:inline:"><![CDATA[
# TODO
#require 'java'
#$height.incVal(0.02)
#puts "Ruby wants something to do. Height: #{$height}"
]]></Carbehavior>

<Carbehavior implName="lang:groovy:inline:"><![CDATA[
// TODO
//height.incVal(0.02);
//System.out.print("Groovy wants something to do. Height:" + height + "\n");
]]></Carbehavior>

<SvgClient><Attribute_String roleName="svgUri"><![CDATA[data:image/svg+xml,

]]></Attribute_String><Attribute_String roleName="setup">${MODELNAME_DEFAULT},${SVGURI_DEFAULT}</Attribute_String></SvgClient>

</XholonWorkbook>