ten little fingers - arvind gupta (4 mb pdf)

Magic Windmill1. Take a pencil with an eraser on one end, or elsetake a 25-cm long fat reed from an old PhoolJharu. Cut 8-10 notches on it. The notches shouldbe 1-cm apart.2. Cut a 1-cm x 4-cm propeller from a thickgreeting card. Make a hole in the centre ofthis fan. Make the hole loose so that the fancan rotate freely on a pin or a thin nail.3. Put a pin or thin nail through the fanhole and fix it in the eraser of the pencil orat the end of the notched stick.4. Hold the notched stick with one hand and stroke anice - cream stick or a ball pen refill on the notches, backand forth. This sets up vibrations in the stick / pencil andthe fan rotates.Make a small parachute from thinplastic or cloth. Roll up theparachute and throw it into the air.Increased drag caused by its widesurface slows down the rate of fall.Make a toy helicopter bygluing a small roundstick to a propeller madeby twisting a card sheet.Twirl the stick in yourhands and make it riseinto the air.Make a simple weathervane out of a cardboard andstring. Place it in the wind.The larger drag of the tailforces it back and makesthe arrow point into thewind.Matchbox MazeThis unusual puzzle designed by a scientist named Van Deventer, has five inside drawers of thematchboxes stuck to their outer cases in different positions. The ideal matchbox size for the puzzleshould be such that its three dimensions are in the ratio of 1:2:3. However, the ordinary Ship brandmatchboxes available in our country will serve our purpose reasonably. Glue the five drawers to theirrespective cases. Now you have to figure out how the drawer of one case slides into the shell of theother. If you are on the right track then the entire assembly will simply fall into place with no need topush or pull. One such assembly is shown. There are two other ways. Can you figure them out?