Students learn better when they verbalize and argue out their ideas. The teacher should demonstrate his walk at a constant speed. The tower and the dropping place should be safe and secure. The teacher may want to wear a hard hat. The teacher cleans up the egg mess if it hits.
Students clean up the mess if it misses.
Be sure that at the end of the run all eggs and egg pieces are in the garbage can. Discussion should focus on what error factors should be considered, such as reaction time, parallax, air resistance, wind, initial velocities and so on. and which are the dominant factors. This is an important part of the activity so that the students will have a chance to understand the complications that have gone into the simple exercises and the detailed physics questions. Each group, whether it hits or misses, must give equations that demonstrate a reasonable plan for when to drop the egg. Each group must show analyses of what the group has done right, what has gone wrong and discuss possible ways for improvement.