Seltzer Rocket
Build a rocket powered by the pressure generated from an effervescing Seltzer tablet reacting with water.
What you need
- Film canister with snap on lid (Fuji)
- Toilet paper roll (double roll size, preferred)
- Heavy Paper (Construction paper)
- Scissors
- Scotch tape
- Markers, crayons, or paints
- Stickers, optional
- Alka-Seltzer tablets (generic works fine)
- Water in a container
- Eye protection (glasses)
What to do
Step 1. Cut straight up the side of the toilet paper roll.
Step 2. Insert the film canister at one end, making sure the end with the lid sticks out about 1/8".
Step 3. Tape along one edge of the toilet paper roll onto the film canister. Roll the toilet paper roll around the canister and tape tightly into place.
Step 4. Cut a circle out of construction paper, cutting a pie shaped wedge out of the circle. Experiment with different sizes of circles to see if it makes a difference in how the rocket reacts upon launch.
Step 5. Roll the paper into a cone shape and tape onto the other end of the toilet paper tube.
How to make the cone.
Step 6. Decorate your rocket with markers, stickers, crayons, or paints.
Step 7. Cut 4 squares out of construction paper to make fins if you wish. Tape on to lower sides of rocket.
Step 8. Take outside: the rocket, water, Alka-Seltzer tablets, and eye protection.
Step 9. Put on your eye protection.
Step 10. Turn the rocket upside down, remove the lid from the canister, and fill 1/4 full with water. Drop in tablet and immediately replace lid and set on ground. Back up!
The
finished rocket.
What's Happening
This activity is a simple demonstration of Newton's three Laws of Motion. The rocket lifts off because it is acted upon by an unbalanced force (First Law). This is the force produced when the lid blows off by the gas formed in the canister. The rocket travels upward with a force that is equal and opposite to the downward force propelling the water, gas, and lid (Third Law). The amount of force is directly proportional to the mass of water and gas expelled from the canister and how fast it accelerates (Second Law).
Experiment with using one or two tablets
into the canister to see if it will shoot up higher. Be sure
to look for the tablets after the rocket fires, we were able
to reuse some of them a couple of times. See what happens if
you change how much water is put in the canister. Be sure to
rinse off your driveway or sidewalk after finishing with your
rockets.
Tips
Some wax paper rolls appear to fit the film canisters, without
having to cut them. Check any other type of rolled products you
may have on hand, you may find another one that fits even better!