## Forces and Balloons

### Paul Scime

#### Description

Students use balloons to investigate and discuss the forces of compression, tension and torque on common birthday balloons.

#### Objectives

The student knows some common contact forces (for example, friction, buoyancy, tension).

#### Materials

-Balloons, one per student. Suggest standard 8- birthday balloons or circus balloons (the balloon animal type). Any type of balloons will work.
-Textbooks, for use as weight on balloons.
-Duplicated student worksheets, see attached file.

#### Preparations

-Become familiar with the background information given in the attached file.
-Further information and extension activities may be acquired by checking the weblinks.
-Make transparencies from attached document.
-Duplicate selected worksheets (one per student) from attached document.

#### Procedures

-Attention getter: Blowing up and/or breaking a few balloons.

-Administer pre-test. This is a pictorial test. Students are to describe the forces they see in the diagrams. (10 Min)

-Objectives: Explain to the student that you will be discussing forces and how they affect the balloon. Students learn the forces that affect the balloon and apply them to everyday life.

-Discussion: Display each transparency (individual copies for each student may be desired). Assist the student in completing the forces review worksheet while explaining each type of force shown in the transparency. The effect of compression, tension and stress are shown on a balloon. Strength in shape is shown on an aluminum soda can. Easy to crush on its side, difficult to crush from top to bottom. (10 – 15 Min.)

-Hand out a balloon to each student. Allow each student to experiment with the forces discussed. Allow the students to stretch the balloon (tension), and place textbooks on the balloon to demonstrate compression. Twisting the balloon the demonstrate torque. (Note a modification of this demonstration is to allow the students to experiment with the amount of air in the balloon versus the amount of compression it can handle before failure (breaking). (20 Min)

-While the students experiment, visit each group and discuss different forces such as shear, static and dynamic forces.

-Homework: State and discuss five or more examples where these forces apply to everyday life.

#### Assessments

Summative assessment: pre-test assignment, student activity questions and answers. Formative assessment: forces review worksheet with responses to discussion and activity questions.

#### Extensions

The forces & balloons activity can be extended to include a Bridge Building or Mouse Trap Car activity. These activities are excellent for grades 6-8. Please see weblinks for more information and materials for these activities.

Free worksheets for bridge building activities are found here.
Prime Technology

Materials for building balsa wood bridges can be found here.
Supplies

Software to support mousetrap car activities can be found here.
Prime Technology

Software to support Bridge Building activities can be found here.
Prime Technology Free

Web supplement for Forces and Balloons