This Instructable was created to be targeted towards Middle Grades (6-8) Educators. This lesson can be taught in the classroom, or even applied outside of the classroom for online courses. Most of the needed supplies are common household items that should be easily accessible to students.

This activity for students will walk you through the process of creating a balloon powered car, focusing on the concepts of energy and power. When teaching this lesson, students should follow the step-by-step tutorial to make their balloon car. After students design, build, and test the first car, they should create a plan to optimize the design and the length the car traveled by utilizing changes or different materials. The materials or changes they utilize to design the second car will be completely up to them, but they MUST have evidence to support why they believe their design will travel further than the initial design. This teaches students the concepts of energy, power, and motion while also teaching them how to efficiently reiterate the design process by designing a second car or making changes to the first car design using reasoning to support their claims.

If students are challenged by this and need support to get ideas flowing on their own designs or changes to the initial car, prompt them with ideas such as:

Adding another energy source
Increasing or decreasing the weight of the car
The effect of using smoother wheels
Changing the body style of the car

Lesson Learning Objectives:

Students will be able to construct a prototype through engineering design using the applied concepts of energy to support their designs.
Students will be able to test and evaluate their designs in order to redesign and optimize the initial car design.
Students will be able to understand and apply the concepts of potential and kinetic energy.

Integration of STELs:

STELs, Standards for Technological and Engineering Literacy, provide foundational understandings and abilities for Technology and Engineering. They are designed as a guide to help better understand these subjects and how to teach them. STELs are composed of three levels: Core Disciplinary Standards, Practices, and Contexts.

Core Disciplinary Standards

These standards are used to represent information, ideas, and processes that are common to all context areas. There are eight standards which encompass the broad areas of technological activity in which humans are engaged. They offer expectations for what students should learn through knowing, thinking, and doing. The Standards that apply to this lesson are:

Integration of Knowledge, Technologies, and Practices
Design in Technology and Engineering Education
Applying, Maintaining, and Assessing Technological Products and Systems

Technology and Engineering Practices

This level of STELs describes universal practices and dispositions that can be applied to both the core standards and contexts. These practices reflect the knowledge and skills students need in order to apply the core standards in the context areas. Out of the eight Practices, the following that apply to this lesson are:

Making and Doing
Critical Thinking
Creativity

Technology and Engineering Contexts

This level of STELs is made up of the eight contexts common to Technology and Engineering. These can also be thought of as content areas, applications, or topics. These eight contexts describe where the core standards are taught or applied. The Contexts applied to this lesson are:

Energy and Power
Transportation and Logistics

Supplies

The supplies for the step-by-step activity are common household items, so should not cost much and may not cost anything for some students. If the materials cannot be found at home, they can all be purchased at your local Dollar Tree at minimal cost.

The supplies and their costs include:

Pack of thin wood skewers - $1 (I used balsa wood because I had a small piece at home)
Super glue - $1 (I used a hot glue gun because I already had one)
Pack of plastic bendy straws - $1 (I purchased at the Dollar Tree)
Duct tape - $1 (I purchased at the Dollar Tree)
Pack of balloons - $1 (I purchased at the Dollar Tree)
Empty plastic water bottle - Free (If needed, water bottle can be purchased for close to $1)
4 Water Bottle Tops - Free (If needed, water bottles can be purchased for close to $1)
Scissors/X-acto knife - Students should already have one
Tape Measurer - $1 (I purchased at the Dollar Tree)

The supplies for the second part of this activity is up to students to choose from. They can use the materials that they already have, or find other common household items to incorporate into their new designs.

Step 1: Gather Supplies for Initial Car Design

Each student will need the following supplies for the first part of this activity. Most of the supplies are common household items which should be easier on students during the times of online instruction.

Empty plastic water bottle
Balloon
Scissors or X-acto knife
3 plastic straws
Duct tape
4 water bottle tops
Thin wood skewers or about 12 in. of balsa wood
Tape measurer

Step 2: Prepare Body of Car

To begin, gather the empty water bottle and scissors/x-acto knife from your materials. This step will include cutting the spaces for the axles on the base of the balloon car (water bottle).

First, cut two holes on one side of the bottle close to the top for spaces for the axle. The space between the two holes should not exceed 1 in.

Refer to the picture above for clarification.

Repeat this step again, but cut the two holes towards the back (or bottom) of the water bottle. This will be the space for the second axle of the car. Refer to the picture above for further clarification.

Step 3: Prepare Body of Car Continued...

This step will include cutting the space for the straw to poke through for the power source. You will need your water bottle with the 4 cut holes from the previous step and your scissors/x-acto knife.

After cutting four holes for spaces for the axles, we should now cut a hole on the opposite side of the bottle.

Make a small hole at about the center of the bottle using your scissors or x-acto knife. Be sure to make this hole on the opposite side of the holes that were cut for the axles.

Step 4: Prepare Axles and Wheels

From your supplies gather 2 straws, 2 bottle tops, balsa wood/wood skewers, and your hot glue gun/super glue.

Cut the balsa wood or wood skewer at an appropriate length (5-6 in.) for one axle of the car.

Next, gather a bottle top and glue. Glue one side of the wood to a bottle top which will serve as a wheel. Be sure to center the wood with the center of the bottle top and ensure that the wood dries straight and not at an angle. To do this, it is recommended to hold the wood firmly on top of the bottle cap until completely dried. Refer to the first picture above, on the left, for clarification.

Then, cut one of your straws to be slightly shorter than the length of the piece of wood.

Once the wood is dried well to the bottle top, put the straw over the wood. This is demonstrated in the picture above, on the right.

Repeat this step for the second axle of the car.

Step 5: Placing Axles

For this step you will need the water bottle, the remaining 2 bottle tops, axles that were made in the previous step, and your glue.

Once your two axles have dried well, slide one end of each axle through the water bottle in the 4 spaces that were cut in Step 2. Refer to the image above, on the left, for further clarification.

Next, glue a bottle top on the other side of each axle that is missing a wheel. Be sure to relieve all of the weight from the wood and the bottle top while it dries. Be sure that the wood is glued to the center of the bottle top and that it dries straight. View picture above for reference.

Once dried, you now have the base of your car including both axles and all four wheels.

Step 6: Energy Source

For this step, we will be creating the energy source of the car. This balloon will serve as the potential energy source of the car. You will need 1 straw, duct tape, and the balloon.

Put the long end of the straw into the balloon. Attach the balloon to the end of the straw with duct tape, ensuring that no air can escape.

Step 7: Placing Energy Source

Gather the body of your car with the axles and wheels and the balloon attached to the straw from the previous step.

Insert the end of the straw through the hole that we cut in the middle of the bottle in Step 3. Guide the straw until it comes out of the neck of the bottle and out of the opening of the bottle.

Refer to the image above for clarification on the placement of the straw.

Step 8: Powering the Car

Congratulations! You have completed the Balloon Car. Now it is time to power the car.

Before operating, make sure to have a smooth surface.

The balloon will serve as the potential energy source of the car and once the air from the balloon is released and the car is powered, this potential energy transforms into kinetic energy which is what makes the car move.

Blow up the balloon (potential energy source) through the straw until desired and then put your finger on the end of the straw to prevent air from escaping.

While still holding the end of the straw, place the car on a smooth surface and then let go of the end of the straw to release the air from the balloon (kinetic energy). Be sure to measure the length that your car traveled with a tape measurer. This measurement is essential for the next part of this activity!

Step 9: YOUR TURN!

It is now each student's turn to use their creativity and previous knowledge on energy to optimize the design of the car and make it travel a further distance.

Students can use the design we created together and make minor changes. Or they can completely change the design if desired.

No matter the design changes, students MUST use logic reasoning and relate back to the concepts of energy to support their design.

If students have trouble brainstorming their designs, prompt them with the ideas that were given in the introduction. Happy Designing!!!

Introduction: Balloon Powered Car Lesson