8th Grade Launches Recycled Rockets

As part of their study of physics and Newton's laws of motion, Barnesville School eighth graders built bottle rockets using recycled materials. With 2-liter soda bottles serving as the rocket bases, items such as paper cups and cardboard were added as wings and noses. February 4 was launch day.
Students took their recycled rockets outside to test which rocket would fly the highest. A bike pump was used to create air pressure, and water in the bottle (or rocket chamber) served as the propellant for the launch.
While one group launched their rocket, the other two groups used an altitude tracker and calculator to record the number of meters it traveled up in the air. Variables that impacted flight distances included rocket design (noses and wings can help with stability or cause drag), the bike pump pressure level, and the amount of water put into the bottles. Students experimented with different pressure levels inside the chamber and different amounts of water. The highest levels tested were 2 inches of water and 70 psi, launching a rocket 15 meters into the sky.
The water bottle rocket experiment demonstrates Newton’s laws of motion.
NASA's Rockets Educators Guide explains: "The launch of the rocket easily demonstrates Newton’s third law. Students can see the water shooting out of the nozzle (action) and see the rocket streak into the sky (reaction). Students can also experiment with different pressure levels inside the chamber and different amounts of water. The rocket will not fly very high if it is filled only with air. The air will quickly rush out during the launch, but its mass is very low. Consequently, the thrust produced is also low (Newton’s second law). By placing water in the bottle, the air has to force the water out first before it can leave the bottle. The water increases the mass expelled by the rocket, thereby increasing the thrust."
Photos are on Facebook.