Rocket+Launch

Challenge # 2 - Water Bottle Rockets
Purpose: To design a rocket which can be launched into the air by adding pressure to a water-filled plastic bottle. The rocket’s design will determine how high it will go and how long it will take to fall back to the ground. The rocket should be designed to stay in the air for as long a time as possible.

Science Skill:
Design Process, Trial and Error

Key Concepts:

 * Force**- a force is a push or a pull. Forces cause objects to accelerate (gain or lose speed)
 * Action and Reaction Forces**– for every action force in nature, there is always an equal and opposite reaction force. In this case, the plastic bottle pushes the pressurized air and water down toward the ground, and the air and water pushes back up on the bottle causing it to accelerate upward.
 * Air Resistance** – air is a material which resists the motion of objects through it. Although it is not as thick as water, it behaves in much the same way – especially when an object is moving through it quickly.
 * Streamline** – The shape of an object determines the amount of air resistance the object will experience as it moves through air or water.

Materials:

 * Soda bottle (16-20 ounce size) (Look for the pressurized bottle shown below, not the flimsy water bottle!)
 * Plastic grocery bag
 * Manila folder
 * String, tape

Instructions:

 * 1) Explain each of the ideas above. Provide examples and demonstrations to clarify your explanations.
 * 2) Evaluate the materials with your buddy. Discuss possible rocket designs and the advantages and disadvantages of adding a nose cone, fins, a parachute, or other features.
 * 3) Create a sketch of the rocket design before you build. Identify the materials which will be used in your construction.
 * 4) Construct your rocket.
 * 5) Test your rocket, and measure how long your rocket stays in the air using a stopwatch.
 * 6) Redesign your rocket if you wish to make changes.
 * 7) Retest the rocket.
 * 8) Evaluate the success of your design.

Follow Up Interview Questions:

 * 1) What pushes the rocket upward? How do you know?
 * 2) How is the motion of the rocket moving upward different from the motion of the rocket falling downward?
 * 3) How did tail fins and a nose cone change the rocket’s motion?
 * 4) How effective was a parachute?
 * 5) Our rockets used water and pressurized air to propel the rocket upward. How are rockets launched by NASA propelled into space?
 * 6) What is the most important thing you have learned from this activity?

PA State Standards in Science and Technology – Grade 4
3.2.4 C. Recognize and use the elements of scientific inquiry to solve problems.
 * Generate questions about objects, answered through scientific investigations.
 * Design an investigation.
 * Conduct an experiment.
 * State a conclusion that is consistent with the information.

3.2.4 D. Recognize and use the technological design process to solve problems.
 * Recognize and explain basic problems.
 * Identify possible solutions and their course of action.
 * Try a solution.
 * Describe the solution, identify its impacts and modify if necessary.
 * Show the steps taken and the results.

3.4.4 C. Observe and describe different types of force and motion.
 * Recognize forces that attract or repel other objects and demonstrate them.
 * Describe various types of motions.
 * Compare the relative movement of objects and describe types of motion that are evident.
 * Describe the position of an object by locating it relative to another object or the background.