howto generate a smooth moving using farseer?

Jul 27, 2011 at 10:46 AM

hi, i made a simple game app for wp7. i have a image and move it down, the code for it looks like:

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            pos.Y = pos.Y + 1;

            base.Update(gameTime);
        }

where pos is a simple vector2

when i run this, the object dont move smooth it looks like a jiggle.

 

my question is, how to use farseer to improve this and make it a smooth movement?