I was reading 3D World Issue #95 and they had a tutorial for Blender in the Questions section. It involved having a ball hit a wall of bricks and knocking them down. This is tedious to animate brick by brick, but relatively simple with the Blender physics engine. The following animation only took me about 15-20 minutes to get set up.
But you may notice a problem here. The ball appears to accelerate as it leaves the bricks. That’s because the tutorial was just a quick example of how to do the task at hand. So I set about to find out what was going on and why my ball was not obeying the conservation of energy. It turns out that the settings as described in the magazine kept continuously giving the ball energy. So I had to adjust it so that it would only get energy at the beginning. After that, I got something much more realistic.