boomaraing

boomaraing (Boomerang) ek prakaar ka astr hai, jiska upayog praacheen misr nivaasi yuddh aur shikaar ke liye karte the aur Australia ke aadivaasi aaj bhi isi roop mein iska upayog karte hain.

banaavat

lakdi ki bani ek pratyaavart boomaraing

boomaraing ki do kismein hoti hain - pratyaavartya (return) boomaraing tatha apratyaavartya (nonreturn) boomaraing. in donon kismon ki aakruti hainsiya ki tarah hoti hai aur ye donon hi lakdi ki banaai jaati hain. Bhaarat mein ispaat tatha haathi daaaint ka bhi upayog inke banaane mein hota hai. inki lanbaai 6 inch se 4 foot, chaudaai lanbaai ki 1/12 tatha motaai chaudaai ka 1/6 hoti hai. pratyaavartya boomaraing ki donon bhujaaon ke madhya 70roo se 120roo tak ka kon hota hai, kintu Australia mein vyavahrut hone vaale pratyaavartya boomaraing ki donon bhujaaon ke madhya 90digri kon, vistaar 18 inch se 24 inch tak tatha kul bhaar 8 auns hota hai. donon bhujaaon ke kendra se jaanevaale kalpit dharaatal ko aadhaar maankar donon bhujaaon ko 2digri se 3digri tak ainthakar tirchha kar diya jaata hai. apratyaavartya boomaraing ka tirchhaapan pratyaavartya ki vipreet disha mein hota hai. boomaraing ki udaan tirchhepan par hi nirbhar karti hai.

feinkane ki vidhi

pratyaavartya boomaraing ko seedha pakadkar pruthvi ke samaantar disha mein feinkate hain aur feinkate samay yathaasanbhav ghoornan (rotation) diya jaata hai. 30 gaj ya adhik doori tak seedha jaane ke baad, yeh baaaini or jhukakar hava mein 150 foot tak oopar uthata hai aur 50 gaj ke vyaas ka vrutt banaakar paaainch chakkar lene ke baad, yeh feinkanevaale ke paas vaapas laut aata hai. apratyaavartya boomaraing ko pratyaavartya karne ke liye 45digri ka kon banaate hue feinka jaata hai, jo bahut doori tak jaata hai. siddhahast vyakti ke haath mein jaakar yeh ek ghaatak astr ho jaata hai. yeh feinkanevaale tatha lakshya donon ke liye ghaatak ho sakta hai.

baahari kadiyaaain