title: Implement a projectile motion and collision detection - response in a 2D top-down game
body: <p>There are a lot of examples concerning projectile motions in 2D games.</p>
  
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  <li>But, what are the equations for implementing a projectile motion on a 2D top down view game? For example, we want to kick a ball and increase its height (just like sensible soccer).</li>
  </ul>
  
  <p>I read that there could be two sprites, one for the ball and one for its shadow that can create an illusion of ball getting higher.</p>
  
  <ul>
  <li>However, how can we implement collision detection and response when the ball hits a post? Do we have to use the z coordinate as well?</li>
  </ul>