Experiment Category:
Objective:
Design and build a canopy walkway. Scientists use canopy walkways to research the fragile rainforest canopy. The rainforest canopy is the uppermost layer of the rainforest, high in the treetops. Many insects, reptiles, amphibians, mammals, and plants live exclusively in the rainforest canopy.
What You Need:
- Pencil
- Paper
- Ruler
- 20 craft/popsicle sticks
- 2 meters (about 6 feet) of heavy thread or light string
- 6 paperclips
- 20 toothpicks
- 6 straws
- 2 chairs
- Glue
- Masking tape
- Measuring tape (or meter/yard stick)
- 14 ounce soup can (full)
To Do and Observe:
Imagine you are a researcher in the rainforests of Peru. To reach your research site high in the treetops, you must build a walkway using only the materials you can carry into the rainforest (listed above).
Your Challenge:
1) Design and build a walkway that includes:
- Two chairs (the seats of the chairs will be viewing platforms).
- A pulley system that can raise a soup can from the floor to the seat of one chair.
- A 25 centimeter high bridge (from the floor) that is 40 centimeters long (from one chair leg to a leg on another chair). The bridge should be wide and strong enough to support the soup can for 30 seconds.
2) Use a pencil, paper, and ruler to sketch your walkway design in actual size. List the materials you plan to use. Describe where you plan to use them. This will help you build your walkway.
3) Once designed, build your walkway out of the craft/popsicle sticks, thread, paperclips, toothpicks, straws, chairs, glue, and tape. You may use the measuring tape (or meter/yard stick) and scissors as tools, but they cannot be part of the walkway. You do not need to use all your materials, but you can't use any more (Remember, you were unable to carry any more into the rainforest).
4) After you build your walkway, test it! Gently place the soup can on the center of the walkway. If the walkway supports the can's weight for 30 seconds, you've created a successful walkway. Now try to raise the can to the seat of the chair with your pulley.
What's Going On:
A canopy walkway is a unique and tricky bridge to build. The walkway must be strong enough to hold the weight of researchers and their equipment. Heavy equipment, supports, and other building materials destroy the fragile ecosystem. Canopy walkways are often designed to support four or five times the weight they need to carry to ensure the safety of the people using them. Can your walkway support five soup cans? If not, what changes can you make so it will? What types of materials can you use?
Parent/Teacher Tips:
Help your child think about the design of the walkway before s/he builds and tests it. List the characteristics of a safe and effective canopy walkway (e.g. it should be strong enough to support the weight of the researchers, it shouldn't destroy the canopy, etc.).