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Title	Projectile and Orbital Motion
ID	1002164118
Created	12 years ago, 1352747170375
Updated	12 years ago, 1346455057958
Code	/*********************************************************** * This is a simple simulation for projectile motion and * orbital motion. * *******************************************************/ var launchAngle = 68; //launch angle in degrees var launchSpeed = 1500; //launch spped in m/s var launchAltitude = 10000; //how high above the surface is the launch var planetMass = 7.35 pow(10, 22); //mass in kg var projectileMass = 100; //mass in kg var planetRadius = 1737 * pow(10, 3); //in meters var projectileRadius = 1; //radius in meters //Should not be changed unless you want to explore //alternate universes :) var gConst = 6.673 * pow(10, -11); //gravitational constant //Where and how big the "planet" gets depicted var metersPerPixel = 30000; var pixDiam = planetRadius / metersPerPixel * 2; var centerX = 200; var centerY = 200; //Smaller the timescale, the more accurate the simulation //but the longer it will take to run var timeScale = 1000; //how much to speed up from real-time var oldTime = millis(); //used to keep track of change in time var r = planetRadius; //keep track of current radius //Coordinates assume that (0, 0) is the center of canvas var x = planetRadius + launchAltitude; //keep track the x position in meters var y = 0; //keep track of the y position in meters //x and y components of velocity var xVel = launchSpeed * cos(90-launchAngle); var yVel = launchSpeed * sin(90-launchAngle); //shift the coordinate (0,0) to be the "center" of the canvas translate(centerX, centerY); //only draw the background once background(0, 0, 0); //Draw the "planet" fill(223, 224, 170); noStroke(); ellipse(0, 0, pixDiam, pixDiam); //Set the stroke color for the projectile path stroke(161, 101, 214); //draw() is repeatedly called to animate the simulation var draw = function() { //how far is the object from the center of the planet r = sqrt(pow(x,2)+pow(y,2)); //only continue to run the simulation if the object //is not below the surface of the planet if (r >= planetRadius) { //Figure out how much time has passed var newTime = millis(); //make sure to adjust dt by timeScale var dt = (newTime - oldTime) * timeScale / 1000; oldTime = newTime; //What is the old g-field of the planet //Using convention of negative meaning toward the //Center of mass of planet var rAccel = -1 gConst planetMass / pow(r, 2); var xAccel = rAccel * x/r; //x-comp of acceleration var yAccel = rAccel * y/r; //y-comp of acceleration //new and avg velocity based on accelerating and //change in time var newXVel = xVel + xAccel * dt; var newYVel = yVel + yAccel * dt; var avgXVel = (xVel + newXVel)/2; var avgYVel = (yVel + newYVel)/2; //Set up for the next iteration of loop xVel = newXVel; yVel = newYVel; //figure out the new x and y coordinate x += avgXVel * dt; y += avgYVel * dt; //draw the pixel of the location point(x/metersPerPixel, -1 * y/metersPerPixel); } };
Folds
Fork	false
Key	ag5zfmtoYW4tYWNhZGVteXIUCxIKU2NyYXRjaHBhZBiWn-_dAww
Votes	115
Spin-Offs	243
Type	PJS
Width	400
Height	400
User Flagged	false
Origin Scratchpad	null
Hidden From Hotlist	false
Restricted Posting	true
By Child	false
Author Nick	Sal Khan
Author Name	sal
Author ID	kaid_326465577260382527912172
Author Profile Access	COACH

Archive Data

Added	7 months ago, 1718275775100
Updated	7 months ago, 1718275775100
Source Deleted	unknown