So, I'm trying to code a game where there is a ball that chases the player, and currently I'm coding the player physics. For some reason, as the player walks back and forth, it gets faster and faster, but I can't figure out why. I think it might have something to do with me multiplying the physicsX variable by .85, but I can't figure out how that would affect it. Here is my code-

```js
var c = document.getElementById("canvas");
var ctx = c.getContext("2d");
var baseX = 100;
var baseY = 50;
var physicsY = 0;
var physicsX = 0;

function coronavirus() {
  ctx.beginPath();
  ctx.fillStyle = "blue";
  ctx.arc(50, 50, 5, 0, 2 * Math.PI, false);
  ctx.fill();
}

function ground() {
  ctx.beginPath();
  ctx.fillStyle = "green";
  ctx.rect(0, 140, screen.width, 10);
  ctx.fill();
}

function person() {
  ctx.beginPath();
  ctx.strokeStyle = "black";
  ctx.arc(baseX, baseY, 5, 0, 2 * Math.PI, false); //head
  ctx.stroke();
  ctx.moveTo(baseX, baseY + 5); //body
  ctx.lineTo(baseX, baseY + 20);
  ctx.stroke();
  ctx.moveTo(baseX, baseY + 20); //left leg
  ctx.lineTo(baseX - 3, baseY + 27);
  ctx.stroke();
  ctx.moveTo(baseX, baseY + 20); //right leg
  ctx.lineTo(baseX + 3, baseY + 27);
  ctx.stroke();
  ctx.moveTo(baseX - 5, baseY + 10); //arms
  ctx.lineTo(baseX + 5, baseY + 10);
  ctx.stroke();
}

function personHitbox() {
  ctx.beginPath();
  ctx.strokeStyle = "black"
  ctx.rect(baseX - 5, baseY - 5, 10, 32);
  ctx.stroke();
}

function personTouchingGround() {
  var personHitbox = {y: baseY - 5, height: 32}
  var ground = {y: 140} 
    if (personHitbox.y + personHitbox.height < ground.y) {
    touchingGround = false;
} else {
  touchingGround = true;
}
}

function personMoving() {
  if (touchingGround == false) {
    physicsY++;
    baseY = baseY + physicsY;
  }
  physicsX = 0;
  window.addEventListener('keydown', (e) => {
  if (e.key == "ArrowRight") {
    physicsX = physicsX + 0.001;
  }
  if (e.key == "ArrowLeft") {
    physicsX = physicsX - 0.001;
  }
  physicsX = physicsX * 0.85  
  baseX = baseX + physicsX;
});

}
function gameloop() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  new coronavirus();
  new person();
  new personHitbox();
  new personTouchingGround();
  new personMoving();
  new ground();
  requestAnimationFrame(gameloop);
}
gameloop();
```

```css
canvas {
  width: 100%;
  height: 100%;
  margin: 0%;
}
```

```html
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <title>repl.it</title>
    <link href="style.css" rel="stylesheet" type="text/css" />
  </head>
  <body>
    <canvas id="canvas"></canvas>
    <script src="script.js"></script>
  </body>
</html>
```