To demonstrate how a rocket liftoff is an application of Newton's Laws of Motion.
One class period
National Education Standards
Science and Technology
Abilities of technological design
Students will develop an understanding of the characteristics and scope of technology.
All people use tools and techniques to help them do things.
Students will develop an understanding of the attributes of design.
Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation and experimentation in problem solving.
Asking questions and making observations helps a person to figure out how things
Students will develop the abilities to use and maintain technological products and systems.
Discover how things work.
Use hand tool correctly and safely and be able to name them correctly.
- Heavy paper (60-110 index stock or construction paper)
- 35-millimeter (mm) film canister
- Student Page
- Cellophane tape
- Effervescing antacid tablet (broken into two equal pieces)
- Paper towels
- Eye protection
- Film canisters are available from camera shops and stores where photographic processing takes place. These businesses recycle the canisters and are often willing to donate them for educational use. Be sure to obtain canisters with the internal sealing lid. These are usually translucent canisters. Canisters with the external lid (one that wraps around the canister rim) will not work. These are usually opaque canisters.
- For best results, students should work in pairs.
- Make samples of rockets in various stages of completion available for students to study. This will aid the students in visualizing the steps of construction.
- Follow the example and cut the paper to form the body tube of the rocket. The tubes may be different heights to promote comparison of rocket design.
- The most common mistakes in constructing the rocket are forgetting to tape the film canister to the rocket body, failing to mount the canister with the lid end down and not extending the canister far enough from the paper tube to make snapping the lid easy.
- Some students may have difficulty forming the cone. To make a cone, cut a pie-slice-shaped piece from a circle and curl the rest of the circle into a cone. See the pattern on the next page. Cones can be any size.
This activity is a simple but exciting demonstration of Newton's Laws of Motion. The rocket lifts off because it is acted upon by an unbalanced force (First Law). This force comes from the buildup of the gas produced inside the canister. As a result, the lid is blown off and the rocket is launched. 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).
Ask students the following questions:
- How does the amount of water placed in the cylinder affect how high the rocket will fly?
- How does the amount of the tablet used affect how high the rocket will fly?
- How does the length or empty weight of the rocket affect how high the rocket will fly?
Image to right: Follow these steps to construct a model rocket. Credit: NASA
Blast Off Student Page
- Hold an altitude contest to see which rockets fly the highest. Launch the rockets near a wall in a room with a high ceiling. Attach a tape measure to the wall. Stand back and observe how high the rockets travel upward along the wall. Let all students take turns measuring rocket altitudes.
- Ask students, "What geometric shapes are present in a rocket?"
- Use the discussion questions to design experiments with the rockets. Graph your results.