9/11/09

Post date: Sep 11, 2009 1:13:52 PM

Bell ringer: How are fluids (liquids and gasses) different from solids?

• • Notes - how planes work

    • Newton's third law - for every action (force), there is an equal and opposite reaction (force)

      • e.g. when you push on a wall, the wall pushes back on you (which is why you don't fall through the wall)

      • The wings of a plane are shaped to push air downward as the plane moves. The air, then, pushes the wings of the plane upward.

    • Bernoulli Principle - pressure is lower in faster-moving fluids

      • e.g. Yesterday's ping pong ball experiments

      • Wings of a plane are shaped to make air move faster on top of the wing than on bottom. This means there is lower pressure above the wing and higher pressure below the wing. The wing tends to get sucked upward by the lower pressure

• Paper Airplane Project

  • • Write step-by-step instructions for making a paper airplane.

    • Trade these instructions with another group

    • Use the instructions you receive to try to make the plane the other group did.

    • Edit and make comments on their instructions as to which parts were clear, and which were confusing

    • Return their instructions, and get your own back.

    • Write a final draft of your instructions, using the suggestions from your partner group

    • On the same page, answer these questions:

      1. What changes did you make to your instructions? How did this help make them more clear?

      2. Explain how Newton's 3rd Law affects how a paper airplane flies. How does your plane use Newton's 3rd law?

      3. Explain how the Bernoulli Principle affects how a paper airplane flies. How does your plane use the Bernoulli Principle

    • We will have 2 competitions for extra credit; one for farthest distance, and one for longest time in the air.

    • Projects are due no later than Monday, 9/14/09