TEN LITTLE FINGERS - Arvind Gupta

SPRINKLER1. Tie a metre long string to the topof a carrot. Slip the free end of thestring through an empty ball penbody. Then tie it to a small potato.2. Hold the pen body inyour hand and beginmaking circular motions- the potato must swingin a circle. As youincrease the speed ofrotation the carrot willrise There is a forceassociated with therotation of the potato.This force pulls away thecentre of the circle and iscalled Centrifugal force.3. This simplesprinkler works onthe same principleTake a one meterlong flexible plastictube - the one usedas a petrol pipe oras a mason’s leveltube. Keep oneend of the tubeimmersed in waterand suck from theother end.4. When waterstarts coming fromthe other end youstart rotating it andslowly raise it.Inertia PumpThis simple pump was designed by SureshVaidyarajan. Any hollow tube - PVC, metalor even a 30 cm long Papaya stem can bemade to pump up waterHold the tube with your left hand and moveit up and down into a bucket of water.Keep the palm of your right hand on thetop of the tube and open and close it witheach up and down reciprocation. Soonwater will start squirting out. Here theup - down motion of the left hand does thepumping while the right palm acts like avalve.5. Water will keep sprinkling out as longas you continue spinning the tube Thisway you can dram out the whole bottle.The Centrifugal force of rotation isenough to suck and lift water from aheight of almost half a metre. You canmake a simple foot valve using a cyclesteel ball and a pen body as a seat.