Book 1

Book 2

Book 3

Book 4

Helper's Guide

Wonderful Wings (p. 6)

• This activity is a basic introduction to how airplanes and birds fly.

• Background/reference information for this activity:

  • Differences between airplanes and birds:

    • Birds wings both move the bird forward (THRUST) and keep the bird in the air (LIFT).

    • Airplanes have wings that keep them in the air (LIFT) and something to move them forward (THRUST).

Airfoil Magic (p.12)

• This activity is an introduction to how Bernoulli’s principle works.

• IMPORTANT NOTE:  This is an explanation of only ONE of the ways wings and air interact to produce lift.  This is NO LONGER considered an adequate explanation of how airplanes stay in the air. 

• Background/reference information for this activity:

  • See Bernoulli's Principle discussion.

Just Blowing Through (p. 32)

• This activity is an introduction to how hang-gliding works.

• Background/reference information for this activity:

  • Review Lesson 2: An Explanation of Air

  • Review Lesson 4: Types of Forces in Flight

  • How gliders work:

    • Gliders rely on wind currents to give them both THRUST and LIFT.  However, they do not need very windy conditions to fly.

    • Hang gliders are generally designed so that for every foot they fall, they glide forward about 13 feet.

    • The pilot in a glider steers with his or her body.

  • What is a "thermal"?

    • A thermal is a rising body of warm air.

    • As the warm air rises, it exerts the force of LIFT on any body within it such as a bird, an airplane or a glider.

    • Birds use thermals to provide LIFT without having to exert any energy of their own.  Otherwise, birds would need to flap their wings to generate LIFT.

  • Check out the following websites for more information:

    • US Hang Gliding Associations FAQ page:

      http://www.ushga.org/faq.asp

    • A hang gliding Java flight simulator:

      http://www.urban75.org/useless/glider.html

   

   

Elevator Magic (p. 26)

• This activity demonstrates how acceleration contributes to weight.

• Background/reference information for this activity:

  • Review Lesson 1: A Basic Physics Lesson

    • A bathroom scale (weight scale) measures the FORCES pulling down on your body.

    • When you stand on a bathroom scale normally, the only force it is measuring is the force of GRAVITY on your body.

    • BUT … FORCE is generated by MASS and ACCELERATION, so if you are in a moving elevator, your MASS is the same but your ACCELERATION is different than it would be just standing in the bathroom.

    • The moving elevator generates its own FORCE.

    • The scale is now measuring both the force of GRAVITY and the force from the ELEVATOR.

    • Force is additive!