physics-simulations

A collection of physics simulations
git clone https://git.ashermorgan.net/physics-simulations/
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atwood-machine.js (4334B)

      1 const App = {
      2     data: function() {
      3         return {
      4             angle: 90,          // The angle of the 2nd weight (degrees)
      5             mass1: 1,           // The mass of the 1st weight (Kg)
      6             mass2: 10,          // The mass of the 2nd weight (Kg)
      7             gravity: 9.8,       // The acceleration due to gravity (m/s/s)
      8             time: 0,            // The time (s)
      9             active: false,      // Whether the simulation is active
     10             refreshRate: 0.01,  // The simulation refresh rate (s)
     11             intervalId: null,   // The value returned by setInterval
     12             infoVisible: false,
     13         }
     14     },
     15     computed: {
     16         /**
     17          * The net force on the 2nd weight
     18          */
     19         netForce: function() {
     20             let gravityX = this.getO(this.angle, this.mass2 * this.gravity);
     21             let netX = (this.mass1 * this.gravity) - gravityX;
     22             return netX;
     23         },
     24 
     25         /**
     26          * The acceleration of the 2nd weight
     27          */
     28         acceleration: function() {
     29             return this.netForce / (this.mass2 + this.mass1);
     30         },
     31 
     32         /**
     33          * The velocity of the 2nd weight
     34          */
     35         velocity: function() {
     36             return this.acceleration * this.time;
     37         },
     38 
     39         /**
     40          * The displacement of the 2nd weight
     41          */
     42         displacement: function() {
     43             let result = 0.5 * this.acceleration * this.time * this.time;
     44             if (result > 3) result = 3;
     45             if (result < -3) result = -3;
     46             if (Math.abs(result) === 3 && this.active) this.toggle();
     47             return result;
     48         },
     49 
     50         /**
     51          * The position of the 2nd weight
     52          */
     53         positionVector: function() {
     54             let x1 = this.getA(this.angle - 90, 1);
     55             let y1 = this.getO(this.angle - 90, 1);
     56             let x2 = this.getA(this.angle, - this.displacement + 3) + x1;
     57             let y2 = this.getO(this.angle, - this.displacement + 3) + y1;
     58             return [x1, y1, x2, y2];
     59         },
     60     },
     61     methods: {
     62         /**
     63          * Handle a keyup event (implements keyboard shortcuts)
     64          * @param {object} e - The event args
     65          */
     66         keyup: function(e) {
     67             if (e.key === "Escape") {
     68                 if (this.infoVisible) this.infoVisible = false;
     69                 else window.location.href = "../";
     70             }
     71         },
     72 
     73         /**
     74          * Toggle whether the simulation is active
     75          */
     76         toggle: function() {
     77             this.active = !this.active;
     78             if (this.active) this.intervalID = setInterval(this.update, this.refreshRate * 1000);
     79             else clearInterval(this.intervalID);
     80         },
     81 
     82         /**
     83          * Reset the simulation
     84          */
     85         reset: function() {
     86             this.time = 0;
     87         },
     88 
     89         /**
     90          * Update the simulation output
     91          */
     92         update: function() {
     93             this.time += this.refreshRate;
     94         },
     95 
     96         /**
     97          * Get the length of the opposite side of a triangle
     98          * @param {Number} angle The angle in degrees
     99          * @param {Number} distance The length of the hypotenuse
    100          * @returns {Number} The length of the opposite side
    101          */
    102         getO: function(angle, distance) {
    103             return Math.sin(angle / 360 * 2 * Math.PI) * distance;
    104         },
    105 
    106         /**
    107          * Get the length of the adjacent side of a triangle
    108          * @param {Number} angle The angle in degrees
    109          * @param {Number} distance The length of the hypotenuse
    110          * @returns {Number} The length of the adjacent side
    111          */
    112         getA: function(angle, distance) {
    113             return Math.cos(angle / 360 * 2 * Math.PI) * distance;
    114         },
    115     },
    116     created: function() {
    117         // Add keyup handler
    118         window.addEventListener("keyup", this.keyup);
    119     },
    120     destroyed: function() {
    121         // Remove keyup handler
    122         window.removeEventListener("keyup", this.keyup);
    123     },
    124 }
    125 
    126 
    127 
    128 // Create Vue app
    129 function createApp() {
    130     // Create app
    131     Vue.createApp(App).mount("#app");
    132 
    133     // Unhide app divs
    134     document.getElementById("input").hidden = false;
    135     document.getElementById("output").hidden = false;
    136     document.getElementById("data").hidden = false;
    137     document.getElementById("info").hidden = false;
    138 }