Page 1
A small pinwheel can begin spinning with just a puff of air or a gust of wind.
一个小风车，可能只要一口气，或者一阵风，就会转起来。正文预览
Page 2
The wind is moving air, and moving air can push on objects in its path.
风其实就是在流动的空气，而流动的空气会推动它路径上的物体。
Page 3
A pinwheel is shaped with tilted blades, so the air does not hit every part in exactly the same way.
风车的叶片是斜着展开的，所以空气吹上去时，并不会在每个位置都产生完全一样的作用。
Page 4
That uneven push creates turning force, which makes the wheel spin around its center.
这种不一样的推动，会形成让它绕中心转动的力量。
Page 5
If the wind is stronger, the pinwheel may spin faster. If the air is weak, it may turn slowly or stop.
风更大时，风车可能转得更快；风很小的时候，它就会转得慢，甚至停下来。继续看同类型内容
