WATER BOTTLE ROCKET:
Build and launch a rocket that really flies using a water bottle, popsicle sticks, a wine cork, tape, crayons Alka Seltzer tablets and water. This experiment covers Engineering (building the rocket), Art (decorating the rocket) and Science (the chemical reaction between the Alka Seltzer and water).
500 ml (16.9 oz) plastic water bottle * wood popsicle sticks * synthetic cork * Alka Seltzer tablets * masking tape * duct tape
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1. Empty your bottle, remove the labels and the cap. Insert the cork 1/4-3/8 inches into the neck of the bottle.
2. Decorate 4 popsicle sticks with cool designs using crayons, pencils or pens. Put your name or initials on at least 2 sticks. These will be the legs for your rocket.
3. Put a piece of masking tape at the top of each popsicle stick so it looks like the letter “T.” Do this for all 4 sticks.
4. Stand the bottle up on the table with the cork end on the table. With the bottle on the table, attach the sticks by taping them to the side of the bottle, making sure all 4 are level so that the bottle stands without wobbling. Resist the urge to pick the bottle up to accomplish this taping, leave it on the table!
5. Wrap the duct tape around the top of the sticks so they are secured to the bottle. Your rocket should stand straight without wobbling. It is ready to go airborne!
HOW TO LAUNCH YOUR ROCKET:
1. Break 3 Alka Seltzer tablets in half (so they fit through the neck of the bottle). Put the Alka Seltzer into your bottle. Add approximately 1/4-1/3 cup of water to the bottle.
2. Quickly put the cork on the bottle 1/4 to 3/8 inch into the bottle. Stand the bottle on the ground or on your launch pad. Stand back and watch it fly!
HOW TO HAVE YOUR GROUP MAKE & LAUNCH IT:
You are going to construct your rocket indoors at tables or desks and then launch it outdoors. The key to success is to have your prep done ahead of time and have your students construct the rocket one step at a time. You can construct and launch the rockets in one session or divide it into two activities. It depends on your class time and the ages and ability of your group
MAKING THE ROCKET:
1. First prep the bottles by emptying them of liquid, getting rid of caps and cutting off any labels. Insert the corks 1/4"-3/8" into the bottle, put them aside.
2. Put 4 popsicle sticks and 4 pieces of masking tape at each student’s place on the table or desk. Put crayons, pencils or pens where students can reach them.
3. Bring the students to the table and have them decorate their sticks any way they like, making sure that they put their name or initials on at least two sticks. I usually allow 3-4 minutes for decorating. If students are not finished, assure them they can decorate the legs some more once the rocket is built.
4. Have students put tape on the end of each stick like the letter “T.”
5. Demonstrate taping the 4 sticks to the bottle while the bottle is standing cork end down on the table. Then show them how you will come around and put the duct tape on. It is important that you demonstrate how the sticks go on while keeping the bottle and sticks level and on the table.
6. Distribute the bottles and have the students adhere the sticks to their bottles. Younger students will require assistance with this step. Have an adult or older helper go around and “duct tape” the rocket legs once they are attached. Students should leave their finished rocket at their table until it is time to go outside for launch.
LAUNCHING THE ROCKET:
1. Have students come outside with their rockets. Assign a number to each student (i.e. 1,2,3…)
2. Have a launching pad: a flat surface or on the ground
3. Talk about the chemical reaction between the water and the Alka Seltzer ingredients.
4. Talk about safety: stay back from the rocket while it is loaded. Do not put your face above the rocket. Never point the cork at anyone because it can cause serious hurt. Always watch a loaded rocket, if it falls over students should avoid the cork and the instructor should immediately right it. The pressurized cork is a serious projectile.
5. Let students know that only the person who owns the rocket can catch it or pick it up after launch. The rocket owner must retrieve their own rocket and the cork.
6. Call the first student number.
7. Have the student hold the cork while you put 6 Alka Seltzer halves and approximately 1/4- 1/3 cup of water in the bottle.
8. The student hands you the cork and you cork the bottle immediately.
9. Give it a slight shake and put it on the launch pad.
10. Watch it fly!
OTHER THINGS YOU CAN DO WITH THIS PROJECT:
1. Launch the rockets at an angle and guess the trajectory (physics). You can do this by placing it in a bin or a box that gives it some angle.
2. Demonstrate the power of pressure by shooting the cork out of the bottle like a projectile. Make sure it is not pointed at any person or the ground. We often shoot “pop flies” into a field by pointing the rocket up and letting the cork shoot.
When water is added to the Alka-Seltzer tablet a chemical reaction occurs, creating bubbles of carbon dioxide gas. More gas is produced, creating pressure inside the bottle until there is enough force to overcome the seal of the cork. The pressure exerts enough force to launch the rocket high into the air. Students will observe that a lighter rocket will go higher and the flight pattern (trajectory) will change according to the angle of the launch (which way it is pointed).
PRESCHOOL SCIENCE VERSION:
The making of rockets is a 15-20-minute indoor activity and the launching is a 20-25-minute outdoor project.
Instead of having every child make their own rocket, you can divide up into groups of 4 students with each group making one rocket. Each group member will decorate a popsicle leg and participate in building the rocket. Each group member will put a piece of Alka Seltzer tablet in the rocket under the supervision of the instructor in charge of rockets.
The rockets that are made can be saved as classroom rockets to be launched again at another time.
VOCABULARY: Chemical reaction, trajectory, force, gas, pressure