Flat space source code (script)

<html>

<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>Flatspace</title>
<Script Language = "JavaScript" >
var prom = new Array(80);
Xposition = 0 ;Yposition = 0 ;Yvel = 0, Xvel = 0; AngleF = 0, AngleSpeed = 0; Speed = 0;
Yacc = 0; Xacc = 0; Degree = Math.PI/180;Fval = 1;Time = 0;Courseval = 0;k =1; Xold = 0; Yold = 0;TargetX = 100000;RangeP2=100;Range = 10;
TargetY = 200000; Xrange = 1000; Yrange = 1000;Radardegree = .001;

function Target(){Xrange = TargetX - Xposition ;Yrange = TargetY - Yposition;RangeP2 = Xrange*Xrange + Yrange*Yrange;Range= Math.sqrt(RangeP2);
Radardegree = Math.atan(Yrange/Xrange);Radardegree = (180/ Math.PI) * Radardegree; RangeP2 = parseInt(RangeP2);Radardegree = parseInt(Radardegree);
alert(" Range = " + Range + "km " + " Azimuth = " + Radardegree + " degrees " + "RangeX = " + Xrange + " RangeY=" + Yrange ) }


function Clear(){Xposition = 0 ;Yposition = 0 ;Yvel = 0; Xvel = 0; AngleF = 0, AngleSpeed = 0; Speed = 0;
Yacc = 0; Xacc = 0;k = 1; Degree = Math.PI/180;Fval = 1;Time = 0;Courseval = 0;k = 1;Xold = 0;Yold = 0;TargetX = 100000;RangeP2=100;Range = 10;
TargetY = 200000; Xrange = 1000; Yrange = 1000;Radardegree = .001 }

function Enter(){k = document.F1.T2.value;k = parseInt(k)*60;AngleF = document.F1.T1.value;AngleF = parseInt(AngleF)}
function Velocity(){Yacc = Fval* Math.sin(AngleF*Degree); Yvel = Yvel + Yacc; Yposition = Yposition + (Yvel + Yold)/2;Yold = Yvel; TargetX = TargetX + 2; TargetY = TargetY+ .3;
Xacc = Fval* Math.cos(AngleF*Degree); Xvel = Xvel + Xacc; Xposition = Xposition + (Xvel + Xold)/2; Xold = Xvel; Speed = (Yvel*Yvel) + (Xvel*Xvel); Speed = Math.sqrt(Speed); Time = Time + (1/1000);
Courseval =Math.atan(Yvel/Xvel);Courseval = (180/ Math.PI) * Courseval;if (Xvel < 0) {Courseval = Courseval + 180}}
function Looper(){for (i = 0;i<k;i++){Velocity()}}
</script>



</head>

<body background="_themes/blends/blegtext.gif" bgcolor="#CCCCCC" text="#000000" link="#993300" vlink="#0000FF" alink="#FF9900">Force and Acceleration 
(a Newton's Law physics educational game)

 
Acceleration: This
simulation allows you to move about  a flat ( 2 dimensional, gravity free) space
in a ion propelled imaginary space ship.  Type in the ship orientation (
force direction) and thrust duration (time, s = .5*a *t^2), and then click ENTER
... button.  This enters desired course and duration into space ship ion
propulsion engine control computer. The computer uses the accelerometer sensor
inputs to regulate thrust so as to maintain desired acceleration.  Engine
burn does not begin and Time does not change until an Engine Control
Button is clicked. The STOP ENGINE button advances time by an amount
specified (Thrust Duration as entered) at zero acceleration.  

Start by moving along a single axis
at slow speed and note how far you travel in an hour.  Though .1 meters per
second per second is less than 1/100 of a earth "g" it is still far greater than what
ion propulsion engine spacecraft can achieve today, but even 1 meter per second
squared may be obtained in the future.  Trip starts at X, Y coordinate
0,0. Ignore the target message until you have traveled through of four quadrants of the cartesian coodinate system. Travel through all four quadrants clockwise
and counter clockwise. Next, Click "Reset" and start playing the intercept target game. Try to get close to target without overshooting it.   
Space Ship
Engineering Control Panel
<form NAME="F1" action="_derived/nortbots.htm" method="POST" onSubmit="location.href='_derived/nortbots.htm';return false;" webbot-action="--WEBBOT-SELF--" WEBBOT-onSubmit >[Engineering Control Panel] 
<input name="T1" size="21">                             
<input name="T2" size="19">      
                         
 
  Enter Ship Orientation(0 - 360 degrees)    Enter Thrust
Duration (Integer 1- 1200 minutes) 
<input type = "button" value = "ENTER SHIP ORIENTATION AND ENGINE BURN DURATION" name="B5"
onClick = "Enter();Target();document.F1.T2.value = k/60;document.F1.T1.value = AngleF" ;> 
Speed (km/sec)
<input name="T3" size="25">    

Course (degrees)<input name="T4" size="25"> 
X (in km) =
<input name="T5" size="27">, Y
(in km) =  <input name="T6" size="27">  
 Time (in kilo-seconds)  <input name="T7" size="27"> 
Engine Control Buttons Below: 
<input type = "button" value="STOP ENGINE" name="B4"
onClick = "Fval = 0,Looper();document.F1.T3.value = Speed;document.F1.T6.value = Yposition;document.F1.T5.value = Xposition;
document.F1.T7.value = Time; document.F1.T4.value = Courseval;">

<input type = "button" value = "SLOW (.1 M/S/S)" name="B6" onClick = "Fval = .0001;
Looper();document.F1.T3.value = Speed;document.F1.T6.value = Yposition;document.F1.T5.value = Xposition;
document.F1.T7.value = Time; document.F1.T4.value = Courseval; " >

<input type = "button" value="Full Speed Adead (1 M/S/S)" name="B7" onClick="Fval = .001;
Looper();document.F1.T3.value = Speed;document.F1.T6.value = Yposition;document.F1.T5.value = Xposition;
document.F1.T7.value = Time; document.F1.T4.value = Courseval; ">

                               
<input type = "button" value ="Reset" name="B8" onClick = "Clear();document.F1.T3.value = 0;document.F1.T6.value = Yposition;document.F1.T5.value = Xposition;
document.F1.T7.value = Time; document.F1.T4.value = Courseval; "> Reenter
course and burn duration after Reset

</form>
Note: Ship Orientation and Course
are independent of each other.

Exercise: Travel to X = 1000km + or - 1.0km  and Y = 1000km +
or - 1.0 km and stop there ( slowing to a velocity less than 10 meters per second
constitutes a stop.) 

</html>

Copy script above and create your own HTML version of FLAT SPACE JavaScribt.

Modify " function Target " so that azimuth reads correctly when Xrange is negative. That is when spaceship X position exceeds Target X position. Frequently we see that in the real world space probes require software updates after launch and must be transmitted to space probe.

Flatspace Source Code