Use cardboard, paper, paste or glue, paper clips, and any other materials you want to try. If you want a pattern designed from a real crane silhouette, click on the small pattern to see a larger sized one. Or try to develop your own pattern, from paper airplane designs or anything else that might work. Classes can test the birds to see which stay aloft the longest, and which fly the farthest. Answers to Flight Lesson Questions Question 1.
Gravity DOES pull on helium balloons.
So gravity pulls air harder than it pulls helium, and the air sinks below the helium. The helium floats higher and higher above the heavy air until it gets high enough that the thinning atmosphere has the same density, and at that point the helium balloon stops rising. Let's say a large falcon grabs for a flying bat with its talons and misses, except one sharp talon slices into the wing. The bat wing, made of thin skin, needs stitches to hold the skin together until it heals, but that isn't possible in nature. So even if the bat narrowly escapes the falcon, if its wing is torn it can never fly again and will eventually die.