Week 4

Session 2

Guiding Question

  • How can we make sand stand tall?

Subquestions

  • What do the four forces look like when an airplane is not straight and level?

  • What happens when you add a propeller to your gliders?

Outcomes

  • Understand four forces and describe what happens to the forces acting on an airplane when it turns, climbs, and descends.

  • Understand the roles of the propeller in flight

CT Components

Simulation

  • Unbalanced forces acting on an airplane

Abstraction

  • Making sense of how a propeller works

How do propellers help an airplane fly?

Small-group Hands-on Scientific Inquiry

Finish last activity if needed

Facilitator opens the activity with discussions with students: “What happens if the airplane is not straight and level? How does this affect the four forces?” Show with vectors. (Use an airplane with vectors pointing out, with the gravity vector on a hook – will always point to Earth) “This can show that if the airplane is going straight up, the gravity and drag are added together and they go against the thrust. In a turn, some of the lift helps the airplane move sideways (lift vector points up and towards a side), but we need more lift to counter the same amount of weight.”

Now add a propeller to the first styrofoam airplane. Now you have thrust. Test the airplane to see how far it can fly with 20 turns of the propeller (whatever number seems appropriate, just needs to be a constant). Does the airplane need to have the weight adjusted? Does the angle of attack make a difference? Record your test results. Which angle of attack flies the farthest?

Watch the video "How do propellers work". Stop the video at 35 seconds and let the students answer the question on why the vehicle with the propeller moved. Continue the video. Stop the video at 1:16 and let the students answer the question. Continue the video. Stop the video at 2:28 and let the students answer the question. Continue the video. Stop the video at 2:58 and let the students answer the question. Continue the video. Then watch "Amy's Aviation" to see how a propeller works on a plane.

The facilitators ask, “what did we learn from these videos?” The students take notes in their journals as the teacher records their answers on the board. Discuss. Then tell the students, “for the next two sessions we will be making the rubber band powered propeller airplanes.” Use the following resource directions and have the students start building their propellers. Once the airplane has been assembled, try to find the best spot (forward and aft on the fuselage) for the wing by throwing it as a glider. Once that has been determined, wind the propeller, making sure it is being wound in the correct direction (looking at the front of the airplane, it should be wound in a clockwise direction). Then, hold the propeller and the airplane and gently toss the airplane and let go of the propeller at the same time. Work on fine turning the path of the airplane by changing the position of the wing. Also, if the airplane is always turning to the left (it most likely will due to the torque of the propeller), one may create a little rudder to counteract this force. To do this, gently bend the back of the vertical stabilizer (where the rudder would be) to the direction you want your airplane to go (to the right).

Steps to build a propeller airplane

1. Using the propeller airplane template, cut out wing and tail pieces (using the big foam tray for the wing; use the small foam tray for tail pieces).

2. Smooth and round edges with the sander.

3. Attach the propeller to the front of balsa wood fuselage.

4. Attach the large rubber band to the propeller and “hook” on the fuselage.

5. Using a small rubber band and WAD, attach the wing to the fuselage.

6. Insert the horizontal stabilizer into the vertical stabilizer (put the tail together).

7. Insert the tail into the slot on the back of the fuselage, tape the back end into place to keep it secure.

Once the airplane has been assembled, try to find the best spot (forward and aft on the fuselage) for the wing by throwing it as a glider. Once that has been determined, wind the propeller, making sure it is being wound in the correct direction (looking at the front of the airplane, it should be wound in a clockwise direction). Then, hold the propeller and the airplane and gently toss the airplane and let go of the propeller at the same time. Work on fine turning the path of the airplane by changing the position of the wing. Also, if the airplane is always turning to the left (it most likely will due to the torque of the propeller), one may create a little rudder to counteract this force. To do this, gently bend the back of the vertical stabilizer (where the rudder would be) to the direction you want your airplane to go (to the right).

Resources

End of Session Reflection and Debriefing

5-10 minutes

Teacher briefly explains the computational thinking (CT) skill embedded in the Problem Solving Process Diagram. Using the problem solving process diagram, the teacher will ask students to identify what kind of problem solving skills/process/computational thinking they used in this session and explain how they used it. The following are some sample questions that can guide the debrief.

  • What did I learn today?

  • What problem solving skills/processes or CT components in this diagram did I use today?

  • How did I use the problem solving skills/processes/CT components?