Traditional Principles of Animation/Follow through
Follow-Through is a companion to the overlapping action. An action almost never comes to a complete and sudden stop. Instead, inertia carries the object beyond the termination point, often causing the object to slowly reverse direction and settle back to the intended stop location. A golfer's swing provides an ideal example of a follow-through. Once the ball is struck, the club (and golfer) follow through the point of contact to complete the swing. What about a pencil that drops to the ground? When it hits, does it stop dead in its tracks? Or, does it bounce around a little, then rolls to a stop? Two cars collide in the middle of an intersection. Do they hit and stick? No, recoil occurs, causing them to reverse direction. Again, an action almost never comes to a complete and sudden stop.