as i was browsing youtube the other day, i came across this video of a kid who had the unique talent of being able to throw a business card with extreme speed and precision. as i sat in awe of his skills, i began to ponder the mechanisms by which he is able to throw such a flimsy object at such high speeds. when the movie plays through a slow motion section, i am able to have a look at the nature of the cards trajectory. I think the reason he can perform this cool task is because he throws the card with a flick of his wrist, imparting a spin on the card as it is propelled forward. like a bullet, the gyroscopic forces the spin creates allow the card to fly stable in the orientation that provides the least amount of air resistance to the card. you will notice in the video that such spin has certain side effects. air resistance acts on one side of the card more than the other, a result of the fact that the spin makes the sides of the card have different velocities relative to the air. this force, along with the gyroscopic force, cause the card to fly tangential to an invisible ark through the air. you would think this makes it hard for the kid to be accurate, yet surprisingly, he seems to do pretty well despite of it. P.S. i don't really know how to attach a video, so be sure to follow the link below. or else.