Impact Velocity From Given Height

<?xml version="1.0" encoding="UTF-8"?>  <XholonWorkbook> <Notes> Khan Academy ------------ Title: Impact Velocity From Given Height Description: Determining how fast something will be traveling upon impact when it is released from a given height Url: http://www.khanacademy.org/video/impact-velocity-from-given-height?playlist=Physics InternalName: impact-velocity-from-given-height YoutubeId: 2ZgBJxT9pbU Keywords: projectile, motion My Notes -------- ledge on a building or cliff height h in meters = 5 m a Person (me) is on the ledge I can jump off the cliff, or drop a rock Rock is one possible falling object initial velocity vi = 0 final velocity vf will have a negative value, because it's falling downwards ignore air resistance; assume there's no air (we're on the Moon) directions for vectors + is up - is down acceleration of gravity a_e = -9.8 m/s^2 displacement = average velocity * change in time s = v_avg * delta t average velocity = (vf + vi) / 2 delta t = delta v / a delta v = a * delta t if height = 5 m final velocity = -9.9 m/s JavaScript with Xholon Bootstrap (function(h){alert(Math.sqrt(2.0*9.8*h)*-1);})(5.0) JavaScript bookmarklet Paste directly into your browser's address bar. javascript:(function(h){alert(Math.sqrt(2.0*9.8*h)*-1);})(5.0) JavaScript with Firebug If you have Firebug installed in Firefox or another browser, then you can run the following directly in your browser's address bar, or with the Firebug console. javascript:(function(h){console.log(Math.sqrt(2.0*9.8*h)*-1);})(5.0) </Notes> <script implName="lang:python:inline:"><![CDATA[ import math h = 5.0 print math.sqrt(2.0*9.8*h)*-1 #http://ideone.com/XHtZA # result: -9.89949493661 ]]></script> <script implName="lang:javascript:inline:"><![CDATA[ var h = 5.0; print((Math.sqrt(2.0*9.8*h)*-1) + "\n"); //javascript:(function(h){alert(Math.sqrt(2.0*9.8*h)*-1);})(5.0) // result: -9.899494936611665 ]]></script> <_-.XholonClass>  <PhysicalSystem/> <Cliff/> <FallingObject> <Rock/> </FallingObject>  <Height superClass="Length"/>  <Displacement superClass="Length"/>  <AccelerationOfGravity superClass="Acceleration"/> </_-.XholonClass> <xholonClassDetails> <FallingObject> <port name="displacement" connector="#xpointer(Displacement)"/> <port name="velocity" connector="#xpointer(Velocity)"/> <port name="acceleration" connector="#xpointer(../AccelerationOfGravity)"/> <port name="cliffHeight" connector="#xpointer(../Cliff/Height)"/> </FallingObject> </xholonClassDetails> <PhysicalSystem> <Rock> <Displacement>0.0 m</Displacement> <Velocity>0.0 m/s</Velocity> </Rock> <Cliff> <Height>5.0 m</Height> </Cliff> <AccelerationOfGravity>-9.8 m/s^2</AccelerationOfGravity> </PhysicalSystem> <Heightbehavior implName="lang:python:inline:"><![CDATA[ import math h = contextNodeKey.val print(math.sqrt(2.0*9.8*h)*-1) ]]></Heightbehavior> <Heightbehavior implName="lang:javascript:inline:"><![CDATA[ var h = contextNodeKey.val; println(Math.sqrt(2.0*9.8*h)*-1); ]]></Heightbehavior> <Blockbehavior implName="lang:bsh:inline:"><![CDATA[ // This works if pasted in as a last child of Block. //height.incVal(0.02); //System.out.print("Java/Beanshell wants something to do. Height:" + height + "\n"); ]]></Blockbehavior> <Blockbehavior implName="lang:jruby:inline:"><![CDATA[ #require 'java' # This works if pasted in as a last child of Block. #$height.incVal(0.02) #puts "Ruby wants something to do. Height: #{$height}" ]]></Blockbehavior> <Blockbehavior implName="lang:groovy:inline:"><![CDATA[ // This works if pasted in as a last child of Block. //height.incVal(0.02); //System.out.print("Groovy wants something to do. Height:" + height + "\n"); ]]></Blockbehavior> </XholonWorkbook>