// Daniel Shiffman

// http://natureofcode.com

​

let angle = 0;

let aVelocity = 0;

let aAcceleration = 0.0001;

let slider;

​

function setup() {

  createCanvas(640, 360);

  slider  = createSlider(-0.01,0.01,0,0.001);

​

}

​

function draw() {

  background(220);

​

  translate(width / 2, height / 2);

  rotate(angle);

​

  stroke(0);

  strokeWeight(2);

  fill(127);

​

  line(-60, 0, 60, 0);

  ellipse(60, 0, 16, 16);

  ellipse(-60, 0, 16, 16);

  aAcceleration = slider.value();

​

  angle += aVelocity;

  aVelocity += aAcceleration;

}