A tower, e.g. the band tower, or any tower or bridge about 6 to 10 meters high where students can climb up. Timers and rulers are available to them but the teacher will not tell them that they may need them. This is an important part of the problem solving procedure. The teacher should answer questions, but do not tell the students how to solve the problem. Let the students in each group decide their own strategies.
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.