## Introduction: Spitball Straw Rockets- Quick, Cheap, and FUN!

Straw rockets have been done over and over with hundreds of different variations, so why not one more?  This version is ultra-fast and super easy, allowing you to make multiple rockets with different designs in a very short time.

I do this project with 7th and 8th grade students in one class period, having them build at least 3 different rockets with different lengths and different size, style, and number of fins.  This allows them to see how different designs may work before we build larger pop-bottle rockets.  There are many other possible applications, please see the last step for more ideas!

Learning Objective:  By building 3 Spitball Straw Rockets, students will be able to compare how different rocket designs perform, understand how thrust and drag affect rockets, and demonstrate Newton's 3rd Law of Motion- For every action, there is an equal and opposite reaction.

## Step 1: Gather Supplies

Very simple list:

Strip of paper about 2" wide and as long as you want to make it
Scissors
Glue Stick
Pen or dowel slightly thicker than the straw
Straw

## Step 2: Make the Body

Trim the piece of paper to the length of your pen or dowel as shown in Picture 1.  If you are using a long dowel, you can glue strips together to make them long enough.

Roll the paper around the pen tightly as shown in Picture 2, and then put glue along the last edge of the strip.  Roll it over a few times to push the edge down tight so the glue will stick!

Slide the tube off of the pen.

Make the Nose Cone by flattening a part of the top and folding about 1/4" of it over as shown in Picture 4.  Glue it down.

That was easy!  Lets make some fins.

## Step 3: Make the Fins

Using the piece you trimmed off of the strip or another scrap, design a fin and cut it out.  Use it to trace other fins as shown in Picture 1.

Once you have all of the fins cut out (remember, try different styles, sizes, and numbers on different rockets!), we can glue them on.  There are two ways to do this.  The easiest is to just put a strip of glue down the edge of a fin as shown in Picture 2 and then glue it flat to the side of the body as shown in Picture 3.  The other way to do it would be bend the edge of the fin, creating a tab to put glue on.  To me, its just an extra unnecessary step, but its your rocket!

Continue attaching the fins, trying to make them as evenly spaced as possible.  Also try to get them as parallel to the body as possible for straight flight.

## Step 4: Launch!

Easiest step of the whole thing- slide the body of the rocket over the straw, put the straw to your mouth, and BLOW!

## Step 5: Ideas for Classroom Use.

There are lots of ways to use this simple project in your classroom.  Here are a few quick ideas:

Demonstrating Newton's Law's- action/reaction of rocket when launched, momentum & inertia, etc.
Center of Pressure vs. Center of Gravity- attach fins to top of rocket instead of bottom and compare flight characteristics
Physics / Trajectory- set up a box or can and have students try to get rocket in the "goal"- tip the box on its side so rockets have to enter from the side (flat trajectory), then tip box up so rockets have to come in from the top (high trajectory)
Thrust and drag- compare large fins to small fins, soft blow to hard blow (or even use an air hose to REALLY launch them across the room...)

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