HBJ/

New Frontiers/

Go Fly a Paper Airplane p. 478/

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R4N19/

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/-/Have you ever flown*D1 a paper airplane? /-/Sometimes it turns*- and loops*- (through the air. )/-/Then it comes*- to rest,=IAV020 soft (as a feather. )/-/Other times=U--02 a paper airplane climbs*- straight up, flips*- over, and dives*- headfirst (into the ground. )/-/What keeps*D1 a paper airplane (in the air? )/-/How can you make*D1I a paper airplane go=IDO080 (on a long flight? )/-/How can you make*D1I it loop=IDO020 or turn?=IDO020 /-/Does wind help*D1I a paper airplane to stay=IDO060 up? /-/What can you learn*D1 (about real airplanes )(from paper airplanes? )/-/Let's*D1I discover=IDO051 some (of the answers. )/-/Take*D1 two sheets (of the same-sized paper. )/-/Crush*D1 one (of the papers )(into a ball. )/-/Hold*D2 the crushed=P--01 paper and the flat paper high (above your head. )/-/Drop*D1 them both (at the same time. )/-/The force (of gravity )pulls*D1 them both downward. /-/Which paper falls*- (to the ground )first? /-/What seems to*D1 keep the flat sheet (from falling=GOP020 )quickly? /-/We live*- (with air )all (around us. )/-/Air is*A1 real [AReven though you can't see*D1 it. ]/-/The air pushes*- back (against the flat paper )and slows*D1 its fall. /-/The paper ball has*D1 a smaller surface pushing=P--04 (against the air, )[ARso it falls*- faster. ]/-/The spread-out wings (of a paper airplane )keep*D1 it (from falling=GOP060 )quickly down (to the ground. )/-/We say*D1 [DOthe wings give*D1 a plane lift. ]/c/But you want*D1I a paper airplane to do=IDO131 more (than just fall=IOP060 )slowly (through the air. )/-/You want*D1I it to move=IDO040 forward. /-/You can make*D1I a paper airplane move=IDO080 forward (by throwing=GOP021 )it. !!!!!!!!