# Building a Balloon Rocket Car

## Overview

During these hands-on, minds-on activities, students will be asked to build balloon powered rocket cars and complete an exercise using skateboards. These activities demonstrate Newton's Laws of Motion, especially the Third Law, which states that for every action there is an equal and opposite reaction.

The activities are simple and inexpensive, yet they provide endless possiblities for expanding lesson plans and meeting learning standards.

The minimum amount of time needed for this lesson is 90 minutes.

The balloon powered rocket car activity was adapted from National Aeronautic and Space Administration's (NASA) Rockets: Physical Science Teacher's Guide with Activities. Lesson design by university student volunteer, Brooke Dashiels.

## Introduction

#### Introductory Activity

Blow up a balloon, but don't tie it. Ask the students to predict what will happen to the balloon when you let it go. Let it go and watch what happens! Here are some questions to start your students thinking about forces:

• What happened to the size of the balloon when it was released?
• Where did the balloon go when it was released?
• What caused the balloon to move when it was released?
• Did all of the air come out of the balloon?
• What pushed the air out of the balloon?

#### Additional Discussion and Questions

The Introductory Activity leads into a discussion of Newton's Laws of Motion and how they can be applied to understanding forces, particularly the forces which act on rockets. Here are some sample questions to get the discussion started:

1. What is a force?
2. Is a heavier object easier or harder to move than a lighter object? Why or why not?
3. Why does a rocket need fuel?
4. What is gravity?
5. How does gravity act on a rocket?
6. Why do the boosters fall off of the space shuttle after it is launched?
7. What are some ways scientists can study the forces which act on rockets in the laboratory?
8. If you were building a car would you want to make it light or heavy? Why?

## Activity 1: Skateboard Excercise

##### For the Skateboard Exercise you will need the following materials:
• two skateboards
• two bicycle helmets
##### Step 1: Helmets
• It is suggested that each participant wears a helmet during the Skateboard Exercise.
##### Step 2: Using the Skateboard
1. Place the skateboards so that the front of one skateboard touches the front of the other skateboard. Place the skateboards on the floor.
2. One participant stands on the middle of each skateboard.
3. The two participants hold out their hands and touch each other's hands, palm to palm.
4. The two participants then gently push off one another. The skateboards should travel away from each other.

## Activity 2: Building the Balloon Rocket Car

#### To build the Balloon Rocket Car you will need the following tools:

• hammer
• nails
• scissors
• ruler or tape measure
• safety goggles

#### For each Balloon Rocket Car you will need the following materials:

• four plastic 2 liter or 20 ounce bottle caps
• three straws (one must be bendable)
• two short wooden skewer sticks
• one piece of corrugated cardboard at least 3 by 4 inches
• masking tape
• duct tape
• one balloon
• pencil

Materials

Source

four plastic 2 liter or 20 ounce bottle caps

recycling center

one straw (one must be bendable)

grocery store

two short wooden skewer sticks

grocery store

one piece of corrugated cardboard at least 3 by 4 inches

recycling center

masking tape

home improvement store

duct tape

home improvement store

one balloon

grocery store

pencil

office supply store

Note: If you feel your students might be unfamiliar with the tools and materials, you should review the tools and materials vocabulary with them before assembling the Balloon Rocket Car.

#### Step 1: Making the Wheels

1. Find a nail that has the same diameter as the skewer stick. Use a hammer and nail to punch a hole into the center of each of the four bottle caps.
##### Step 2: Making the Car Body
1. Use problem solving skills to determine and cut out the rocket car body out of corrugated cardboard.
2. Estimate the width of the rocket car body by looking at the length of the skewers, straws, and bottle caps. (Note: The rocket car body does not necessarily need to be a particular shape.)
3. Estimate the length of the rocket car body by taking into consideration that the participants will need to be able to blow up the balloon through the straw.
##### Step 3: Designing the Axles
1. Use problem solving skills to determine and cut the straws for the front and rear axles. (Note: the length of the straws should be approximately the same size as the width of the cardboard.)
2. Use masking tape to tape the straws to the underside of the body.
##### Step 4: Attaching the Wheels
1. Thread the skewer through the straw.
2. Thread one bottle cap onto each end of the skewer.
3. Repeat this procedure for each axle.
##### Step 5: Making and Attaching the Propulsion System
1. Blow up a balloon three or four times to stretch it out.
2. Attach the balloon to the bendy end of the straw with duct tape.
3. Masking tape the straw with the attached balloon perpendicular to the axles on the top of the car body. (Note: The straw must extend beyond the rocket car body on both ends so that the participant can blow up the balloon through the straw and also so that the balloon can expand without hindering the movement of the wheels.)

##### Step 6: Using the Balloon Rocket Car
1. Blow up the balloon through the straw.
2. Once the balloon is blown up, pinch the straw closed.
3. Put the rocket car on the ground and release the straw.
4. Watch it go!

## Activity Questions

#### Part 1: Skateboard Exercise

1. Make a prediction about the distance your skateboard and your partner's skateboard will go when you push off each other.
2. Measure the distance your skateboard and your partner's skateboard went when you pushed off each other.
3. Describe what happened when you and your partner stood on the skateboards and pushed off each other.
4. Describe the similarities and differences between how the Skateboard Exercise works and what happened to the balloon in the Introductory Activity.
5. On the back of this paper, draw a picture of the direction each skateboard moved and use arrows to show the forces which act on the skateboards when they are moving.

#### Part 2: Balloon Rocket Car Activity

After building the Balloon Rocket Car, blow the balloon up through the straw. Pinch the straw so the air can't get out.

1. Make a prediction about how far the car will go when you release it then put the car on the floor and let it go!
2. Measure the actual distance the car went when you released it.
3. Describe what happened to the balloon when you released the car.
4. Describe the similarities and differences between how the rocket car works and what happened to the balloon in the Introductory Activity.
5. On the back of this paper, draw a picture of the car, label the parts and use arrows to show the forces which act on the car when it is moving.
##### Extra Credit
1. Explain what would happen if you put rocks, or other heavy objects on the car body.
2. Describe the similarities and differences between the rocket car activity and the skateboard exercise.

## Assessment

Our assessment methods were the same for Illinois and National Standards.

Our assessment methods were the same and for Early and late Elementary School students. What changed was the level of the questions asked and the discussion.

We used informal assessment methods in the form of verbal questions and discussion. Formal methods of assessment included drawings, and written answers to questions, and the development of articles for the BOAST Kids Newsletter.

#### During the Lesson

The participants used inquiry strategies to successfully build the balloon rocket car. Then they tested the device and reported on its use. Throughout the lesson, the participants discussed Newton's Third Law.

After building the balloon rocket car, the participants were trying their cars out in the hallway, where there is a ramp with a slight incline. The participants tried their cars out on the ramp. The result was that the cars would go down the ramp, but they would not go up the ramp. One of the participants thought that his car might go up the ramp if the car had an additional balloon to give it more power. He put another balloon on a straw and attached both of the straws to the top of the car body. When he released the car with the two balloons at the bottom of the ramp, it went up. This action, by a kindergarten student, was followed by many participants adding additional balloons to their cars.

While experimenting with the skateboard, it seems that most of the children were able to understand one of the most basic concepts presented in the lesson: Newton's Third Law of Motion which applies to the inertia of an object, or as one child said, "Big stuff is harder to move." In one instance, a child was on one skateboard while a university student volunteer was on the other. After the two had pushed off each other a few times, and the child had traveled quite a ways each time, the volunteer asked her why she moved so much and he didn't. She replied, "Because big stuff is harder to move!" This observation by a third grader was especially good because prior to the lesson, most children thought that one person would move further than the other because the bigger person was pushing harder.

#### At the Conclusion of the Lesson

At the conclusion of the lesson, a discussion was held to determine the level of participant understanding concerning the lesson introduction and activities. Some of the discussion centered around the questions asked in Part 1 and in Part 2 of the worksheet.

Other questions centered around Newton's Third Law of Motion and the Lesson Introduction and activities. Some of these questions were:

• Describe the forces which acted on the balloon in the introductory activity.
• How does Newton's Third Law explain what happened to the balloon in the introductory activity?
• How does Newton's Third Law explain how the Rocket Car works?
• How does Newton's Third Law explain what happened to the participants during the Skateboard Exercise?

Each of the children who participated in the lesson was able to answer these questions at his/her own level.

## Suggestions for expanding this activity

#### The Skateboard Exercise

• Repeat the exercise and have the students change partners so that they can determine whether changes in mass, height, gender, or other variables result in changes in the distance travelled by the skateboards.
• Repeat the exercise using different kinds of skateboards to see if this changes the distance travelled by the skateboards.

#### The Balloon Rocket Car Activity

Try these variations on building the Balloon Rocket Car:

• Build several cars using a different shaped body for each one.
• Use other materials to build the rocket car body. For example styrofoam, wood, or various thicknesses of cardboard.
• Use other materials for the wheels such as styrofoam, cardboard circles, milk bottle caps...
• Try attaching the wheels in a different way. For example, pin the wheels directly to the side of the car body.
• Try blowing the balloon up different amounts.
• Try different balloons, small, large, round, or cylindrical.
• Try adding more than one balloon to the car.

Try these variations on using the Balloon Rocket Car:

• Try running the rocket car on different surfaces such as a tile floor, rug, sidewalk, dirt or snow.
• Try running the rocket car on slopes.

## Illinois Learning Standards that Apply to this Lesson

The following standards are from the Illinois Learning Standards, adopted by the Illinois State Board of Education on July 25, 1997. Take a look at the complete Illinois Learning Standards for Science, Mathematics, and English/Language Arts.

### Early Elementary

Subject Goal Standard Application to this Lesson
Science State Goal 11: Understand the processes of scientific inquiry and technological design to investigate questions, conduct experiments, and solve problems. A. Know and apply the concepts, principles, and processes of scientific inquiry.
• 1a. Describe an observed event.
B. Know and apply the concepts, principles, and processes of technological design.
• 1c. Build the device using the tools and materials provided.
• 1d. Test the device and record the results using given instruments, techniques, and measurement tools.
• 1e. Report the design of the device, the test process and the results in solving a given problem.
Participants will use the processes of scientific inquiry to apply Newton's Laws of Motion to building and using Balloon Powered Rocket Cars and completing the Skateboard Exercise. For 1c, see the Step by Step Instructions for the Rocket Car.
Science State Goal 12: Understand the fundamental concepts, principles and interconnections of the life, physical, and earth/space sciences. D. Know and apply concepts that describe force and motion and the principles that explain them.
• 1a. Identify examples of motion e.g., moving in a straight line, vibrating, rotating).
• 1b. Identify observable forces in nature (e.g., pushes, pulls, gravity, magnetism).
Participants will learn about Newton's Laws of Motion, especially the Third Law as it applies to rockets, the Balloon Rocket Cars and the Skateboard Exercise.
Mathematics State Goal 7: Estimate, make, and use measurements of objects, quantities and relationships and determine acceptable levels of accuracy. A. Measure and compare quantities using appropriate units, instruments and methods.
• 1a. Measure length, volume and weight/mass using rulers, scales and other appropriate measuring instruments in the customary and metric systems.
Participants will measure the cardboard used for the body of the rocket car. They will also measure the distance traveled by the rocket cars and the skateboards.
English/Language Arts State Goal 1: Read with understanding and fluency. C. Comprehend a broad range of reading materials.
• 1a. Use information to form questions and verify predictions.
During this hands-on science lesson, participants will comprehend instructions for completing the lesson activities and answer questions about them.
English/Language Arts State Goal 3: Write to communicate to a variety of purposes. C. Communicate ideas in writing to accomplish a variety of purposes.
• 1a. Write for a variety of purposes including description, information, explanation, persuasion, and narration.
• 1b. Create media compositions or productions which convey meaning visually for a variety of purposes.
Participants will draw, describe and explain how the Balloon Rocket Car works. They will also explain how Newton's Laws of Motion apply to this activity and the Skateboard Exercise.
English/Language Arts State Goal 4: Listen and speak effectively in a variety of situations. A. Listen effectively in formal and informal situations.
• 1b. Ask questions and respond to questions from the teacher and from group members to improve comprehension.
• 1c. Follow oral instructions accurately.
B. Speak effectively using language appropriate to the situation and audience.
• 1a. Present brief oral reports, using language and vocabulary appropriate to the message and audience (e.g., show and tell).
• 1b. Participate in discussions around a common topic.
Participants will respond to questions in informal and formal settings during this hands-on science lesson. Participants will discuss how a Balloon Rocket Car works and explain the results of the Skateboard Exercise.

### Late Elementary

Subject Goal Standard Application to
this Lesson
Science State Goal 11: Understand the processes of scientific inquiry and technological design to investigate questions, conduct experiments and solve problems. B. Know and apply the concepts, principles, and processes of technological design.
• 2c. Build a prototype of the design using available tools and materials.
• 2d. Test the prototype using suitable instruments, techniques, and quantitative measurements to record data.
• 2e. Assess test results and the effectiveness of the design using given criteria and noting possible sources of error.
• 2f. Report test design, test process, and test results.
Participants will use the processes of scientific inquiry to understand Newton's Laws of Motion while building and using Balloon Powered Rocket Cars and completing the Skateboard Exercise. For 1c, see Step by Step Instructions for building the the Rocket Car, and the Skateboard Exercise.
Science State Goal 12: Understand the fundamental concepts, principles and interconnections of the life, physical, and earth/space sciences . D. Know and apply concepts that describe force and motion and the principles that explain them.
2b. Demonstrate and explain ways that forces case actions and reactions (e.g., magnets attracting and repelling; objects falling, rolling, and bouncing).
Participants will learn about Newton's Laws of Motion, especially the Third Law as it applies to their Balloon Rocket Car and the Skateboard Exercise.
Mathematics State Goal 7: Estimate, make, and use measurements of objects, quantities and relationships and determine acceptable levels of accuracy. A. Measure and compare quantities using appropriate units, instruments and methods.
• 2a. Calculate, compare and convert length, perimeter, area, weight/mass and volume within the customary and metric systems.
Participants will measure the cardboard used for the body of the rocket car. They will also measure the distance traveled by the rocket car and the skateboards.
English/Language Arts State Goal 1: Read with understanding and fluency. C. Read with understanding and fluency.
• 2a. Use information to form and refine questions and predictions.
• 2d. Summarize and make generalizations from content and relate to purpose of material.
During this exercise, participants will comprehend instructions for building the Balloon Rocket Car and completing the Skateboard Exercise. They will also answer questions throughout the lesson.
English/Language Arts State Goal 4: Listen and speak effectively in a variety of situations. B. Speak effectively using language appropriate to the situation and audience.
• 2b. Ask and respond to questions related to oral presentations and messages in small and large group settings.
Participants will respond to questions in informal and formal settings during this hands-on science lesson. Participants will discuss how a Balloon Rocket Car works and explain the results of the Skateboard Exercise.

## National Science Education Standards that Apply to this Lesson

This is one lesson in a unit on space. During the unit participants learned about the solar system and man-made space craft. This particular lesson's focus is the application of Newton's Laws of Motion, especially the Third Law, to rockets.

Take a look at the National Science Education Standards.

Standard Level Application to this Lesson
6.1 Science as Inquiry K-4, 5-8, 9-12
Abilities necessary to do scientific inquiry
Participants will use scientific reasoning and critical thinking to build and operate a balloon-powered rocket car and complete the Skateboard Exercise. (For more details, see the Step by Step Instructions for building the Rocket Car, and the Skateboard Exercise.)
Understanding about scientific inquiry Participants will ask questions, conduct investigations, and gather information to help them understand how Newton's Laws of Motion, especially his Third Law, can be applied to the lesson activities.
6.2 Physical Science K-4
Position and motion of objects
In the introductory discussion, participants will learn about the forces that act on rockets. Following this discusion, the focus of the lesson wil be placed on Newton's Third Law.
5-8, 9-12
Motions and Forces
In the introductory discussion, participants will learn about the forces that act on rockets. Following this discusion, the focus of the lesson wil be placed on Newton's Third Law.

### Curriculum Standards that Apply to this Lesson

Take a look at the complete curriculum standards of the National Council of Teachers of Mathematics.

Standard Level Application to this Lesson
Standard 1: Mathematics as Problem Solving K-4
• Use problem solving approaches to investigate and understand mathematical content.
• Formulate problems from everyday and mathematical situations.
• Develop and apply strategies to solve a wide variety of problems.
• Verify and interpret results with respect to the original problem.
• Acquire confidence in using mathematics meaningfully.
Participants will face the problem of determining the size of the body of their rocket car. (For more details, see the Step by Step Instructions.) Participants will discuss their ideas with others.
5-8
• Use problem solving approaches to investigate and understand mathematical content.
• Formulate problems from situations within and outside mathematics.
• Develop and apply a variety of strategies to solve problems with emphasis on multi-step and nonroutine problems.
• Verify and interpret results with respect to the original problem situation.
• Generalize solutions and strategies to new problem situations.
• Acquire confidence in using mathematics meaningfully.
Participants will face the problem of determining the size of the body of their rocket car. (For more details, see the Step by Step Instructions.) Participants will discuss their ideas with others.
Standard 10: Measurement K-4
• Understand the attributes of length, capacity, weight, mass, area, volume, time, temperature, and angle.
• Develop the process of measuring and concepts related to units of measurement.
• Make and use estimates of measurement.
• Make and use measurements in problem and everyday situations.
Participants will focus on the unit of length. They will be asked to estimate length measurements for the body of their rocket car. Then they will use a ruler to draw the body of the car. (For more details, see the Step by Step Instructions.) Participants will also measure the distance their car traveled.
Standard 13: Measurement 5-8
• Extend their understanding of the process of measurement.
• Estimate, make, and use measurements to describe and compare phenomenon.
• Select appropriate units and tools to measure to the degree of accuracy required in a particular situation.
• Understand the structure and use of systems of measurement.
• Extend their understanding of the concepts of perimeter, area, volume, angle measure, capacity, and weight and mass.
• Develop the concepts of rates and other derived and indirect measurements.
• Develop formulas and procedures for determining measures to solve problems.
Participants will focus on the unit of length. They will be asked to estimate length measurements for the body of their rocket car. Then they will use a ruler to draw the body of the car. (For more details, see the Step by Step Instructions.) Participants will also measure the distance the cars and skateboards traveled.