title: Increase body speed with applyLinearImpulse box2d
body: <p>Im trying to make body move with increaseing speed. At first its starts to accelerate but it reaches a constant speed shortly after. How do I make it keep accelearte? </p>
  
  <p>My code looks like this: </p>
  
  <pre><code> world = new World(new Vector2(0, 0), true);
  
      if (Gdx.input.isKeyPressed(Input.Keys.D))
          body.applyLinearImpulse(400f, 0, pos.x, pos.y, true);
      if (Gdx.input.isKeyPressed(Input.Keys.A))
          body.applyLinearImpulse(-400f, 0, pos.x, pos.y, true);
      if (Gdx.input.isKeyPressed(Input.Keys.W))
          body.applyLinearImpulse(0, 400f, pos.x, pos.y, true);
      if (Gdx.input.isKeyPressed(Input.Keys.S))
          body.applyLinearImpulse(0, -400f, pos.x, pos.y, true);
  </code></pre>