Chapter 3 | 21balloons2021

Chapter 3: A Description of the Globe

Professor Sherman arrives in San Francisco and is escorted to the Western American Explorer's Club, where he begins to tell his story to a captive audience! He begins by telling about his original plans for flying around the world and the "Globe" he built as his means of travel. Read to learn about this original design and all the decisions the professor had to make about the materials that would be just right for building it and what he would need for his trip!

Anatomy of a Hot Air Balloon

How Things Fly

How In The World...

Does a Hot Air Balloon Work?

Hot air balloons are one type of aircraft. (The four categories of aircraft are airplanes, gliders, rotorcraft, and hot air balloons.) There are two ways a balloon can rise:

It can be filled with a gas that is lighter than air, such as helium. Helium is the second-lightest element, and the main sources for helium are natural gas fields (especially those in the states of Texas, Oklahoma, and Kansas).
It can be inflated with air that is heated sufficiently to make it "lighter" than the air outside of the balloon. Heating air makes it less dense, making it "lighter." Gas balloons and hot air balloons float because they are lighter than the air they displace.

Task 1: Complete the Survey

Productive and efficient teams result from groups that have diverse skills and a variety of strengths. Students will complete the Survey for Groups, and teachers will use survey data to assign balloon construction teams of 2-3 students based on complimentary skills.

Task 2: Review and Evaluate Balloon Designs- Evaluative Thinking

Working with your team, evaluate the different balloon shapes and sizes.

Think about the following: What design features create more lift and stability? What construction factors impact lift?
View the images and slide show below for design inspiration. You will make your own hot air balloon next week.

Traditional Hot Air Balloon Designs

Task 3: Trash Bag Balloon Model - Critical Thinking

In this activity, you will construct a working model of a hot air balloon!

Use the handout to choose a design for your balloon.
Be careful to check for holes prior to launch.
With the teacher, inflate your balloon.
Use a stopwatch to time your balloon.
Complete the Reflection:
- Which Balloon Model did you choose?
- Why did you make this choice?
- How long did your balloon float?
- What design changes can you implement to create more lift?
- Did this work?
- What were the challenges you faced in making your balloon?