TEN LITTLE FINGERS - Arvind Gupta

AIR TOP1. Take a thick card disc 7-cmin diameter. Mark out the linesas shown.2. Cut along the three sides ofthe flaps with a sharp blade.3. Bend theflaps upwardsas shown.Funny Money4. Stick a pin or athin nail through thecentre of the disc,leaving about 1 cmprojecting below.This will be thepivot point of thetop.6. Now hold thedisc lightly againstone end of anempty thread spoolwith your finger,letting the long endof the pin stick upthrough the hole inthe spool. Blowthrough the otherend of the spool.5. Applyglue, orFevicolaround thepin to holdit in place.7. The stream of air youblow strikes the vanesradially and makes themspin. The stream of airalso creates a lowpressurezone, that holdsthe disc against thespool, Once you stopblowing, the top willdrop from the spool andcontinue to spin on thetable.1. Pull an aluminiumhanger into adiamond shape.2. Make a hole inan injection bottlecap and insert it inthe hook.3. Place a coin onthe rubber cap.Swing the hanger ina full circle. Continuespinning fast. Thecoin will not fall.4. When you stop the coin willstill be perched on the cap.This is a very dramatic way todemonstrate centripetal force.