Natural Selection and Ring Gliders

Size: px

Start display at page:

Download "Natural Selection and Ring Gliders"

Emil Malone
5 years ago
Views:

1 Natural Selection and s Introduction: The purpose this lab is to use paper aircraft to model the process natural selection. A basic understanding aircraft design is not necessary to complete this lab but it will help in understanding why some aircraft fly better than others. Parts an aircraft: Source: The ailerons control roll or longitudinal motion the aircraft. The elevators control pitch or the lateral motion the aircraft. The rudder controls yaw or the vertical motion the aircraft. Basic aircraft design: The basic principles that allow actual airplanes to fly also apply to paper airplanes. It must glide well and have good stability. (Crotty) To ensure stability, the aircraft must be symmetrical along the longitudinal axis. An imbalance in the shape the s will cause the aircraft to roll. An imbalance in the shape the s will cause the aircraft to yaw, or turn. Putting the center gravity closer to the s will ensure stability around the lateral axis so the aircraft does not pitch. Putting a paper clip near the the aircraft moves the center gravity forward. For the aircraft to glide well, it must have a high lift-to-drag ratio. The lift-to-drag ratio is the amount lift generated by the divided by the drag it creates moving through the air. Lift is the upward force that counteracts gravity and keeps a plane in the air. Drag is the resistance the air exerts on the forward motion a plane. The lift-to-drag ratio changes with the angle attack, the angle at which it is thrown. An angle about five to six degrees is best for paper airplanes. (Crotty) The aspect ratio is the primary factor in determining the lift-to-drag ratio a. The aspect ratio the aircraft is the distance from the tip one the tip the other divided by the average width the. A high aspect ratio indicates long narrow s, while a low aspect ratio indicates short stubby s. An increase in aspect ratio decreases drag. Basic tenets Natural selection: Natural selection is the process by which populations change over time. There are four key tenets natural selection.

2 . Overproduction fspring more individuals are produced than can survive. Variation among species variation is heritable. Offspring with most favorable traits survive to reproduce 4. Populations change over time We will use the basic tenets natural selection to improve our design the ring glider. gliders: gliders are designed by taping two loops paper to a straw. The loops should be perpendicular to the straw so that when you look down the end the straw you see perfect circles. Lab: (adapted from Hallet s Natural Selection the Carmel Origami Bird) Materials: Paper, three straws, tape, die, penny, metric tape measure, ruler, paper clips Procedure:. Make the original ring glider. a. Cut two strips paper cm x 0 cm. b. Loop each strip paper with a cm overlap. c. Tape each strip cm from the end the straw. d. Align the loops so that when you look from the nose to the tail the aircraft, the loops are perfectly aligned circles. e. Put a paper clip at one end and mark it the nose the ring glider. f. Number the straw this ring glider.. The best flying ring glider in each generation will survive to the next generation and produce two more ring gliders with one variation each. The worst flyers will be used for parts.. To make the other two ring gliders: a. Flip the coin to determine where the variation occurs. i. Heads = is modified ii. Tails = is modified b. Toss the die to determine how the will vary. i. = position moves cm toward the end straw ii. = position moves cm toward the middle the straw iii. = circumference (distance around the ) increases cm iv. 4 = circumference (distance around the ) decreases cm v. 5 = width increases cm vi. 6 = width decreases cm * if the die toss results in the loss a, toss again*. 4. Build each ring glider according to the new specifications. Attach a paperclip at the

3 Data: nose end. 5. Number the straws the two new ring gliders and, respectively. 6. Toss the gliders with a gentle, overhand pitch. Practice before comparing your gliders. 7. The glider that flies the farthest will survive to the next generation and the variations will be made from it. The other gliders will be used for parts. 8. Record your data in the data table. 9. Do this for four generations. Generation tail 9 9 flight *Note only one dimension will be different between glider and glider, and only one between glider and glider. Put a check next to the best flyer. Generation. Write the dimensions the best flyer from generation into the appropriate row. Then, using the dimensions the best flyer, determine the dimensions the two. Make the new gliders from the parts the worst flyers. tail flight Generation. Write the dimensions the best flyer from generation into the appropriate row. Then, using the dimensions the best flyer, determine the dimensions the two. Make the new gliders from the parts the worst flyers.

4 tail flight Generation 4. Write the dimensions the best flyer from generation into the appropriate row. Then, using the dimensions the best flyer, determine the dimensions the two. Make the new gliders from the parts the worst flyers. tail flight Analysis Questions. What were the dimensions the most successful glider from generation 4? tail Circumferenc e Circumferenc e. Calculate the aspect ratio for the most successful glider. Aspect ratio = diameter /width. Answer questions thoroughly in complete sentences.. Did this process result in better flying birds?. Explain the way this lab models natural selection. 4. If you kept repeating this process for thousands generations, would it inevitably result in the best design for a ring glider in this particular location?. Explain.

5 5. Compare the specifications your most successful glider with others in the class. Were all the most successful gliders identical?. Describe differences. Why are they not all identical? 6. If each group continued this process for thousands generations, would the gliders become similar to each other? Explain. 7. Evolution is the result variation and selection. a. How did your experiment produce variation among the gliders? b. How did your experiment select which glider survived to the next generation? 8. How is this lab inaccurate in sho genetic variations? What are other sources genetic variation? 9. How would the least successful glider appear if you selected for the worst flyer in each generation? Citations: Hallett. Natural Selection the Carmel Origami Bird. 7 March 008. Web. 8 November John P. Crotty. Paper Airplanes. Yale-New Haven Teachers Institute. 00. Web. 8 November 00.

Introduction to Technology

Introduction to Technology PRINCIPLES OF FLIGHT Grade 6 BIGELOW Technology Education MIDDLE SCHOOL Newton, MA 05-05-04 P r in c i p l e s o f F l ig h t One of the most innovative and imaginative transportation