Class 6 Science Chapter 5: Measurement of Length and Motion (Hinglish Notes)

Sharir ke hisson se naapna

Chapter Deepa se shuru hota hai, Haryana ki gyaarah saal ki ladki, jise nayi uniform chahiye. Dukaandaar dhaatu ki rod se do metre kapda naapta hai, darzi flexible tape use karta hai, aur uski mummy darzi se char angula, yaani chaar ungliyon ki chaudaai, badhaane ko kehti hain. Deepa ke dost yaad karte hain ki log kapda haath ki lambaai se aur khet kadmon ya pairon se naapte the.

Dost apni class ki table baalisht (handspan) se naapte hain aur alag jawab paate hain: 13, 13 se thoda zyada ya kam, 13 aur 14 ke beech, aur 14. Wajah ye hai ki unki baalisht alag-alag size ki hai. Naap ke do hisse hote hain, ek number aur ek unit: 13 baalisht mein 13 number hai aur baalisht unit. Body units insaan-insaan mein alag hoti hain, isliye humein aisi unit chahiye jo sabko ek hi jawab de.

Bharat mein naapne ka itihaas bahut purana hai. Angula (ungli ki chaudaai), uske multiples, dhanusa aur yojana jaisi units purane Bharatiya sahitya mein milti hain aur cheezein, imaaratein aur shehar banaane mein use hoti thi; badhai aur darzi aaj bhi angula use karte hain. Harappa ki jagahon ki khudaai mein nishaan bani aisi cheezein mili hain jo scales ho sakti hain.

Standard units

Jab log safar karne lage, to alag-alag jagah ki units se uljhan hone lagi, isliye deshon ne standard units par sahmati banaayi: International System of Units, yaani SI units. Length ki SI unit metre hai, symbol m. Ek metre mein 100 centimetre (cm) hote hain, aur har centimetre mein 10 millimetre (mm); 1 mm sabse chhoti length hai jo 15-cm scale naap sakti hai. Lambi dooriyon ke liye kilometre (km) use karte hain.

1 km = 1000 m · 1 m = 100 cm · 1 cm = 10 mm

Kuch scales par inch bhi hote hain, jahan 1 inch = 2.54 cm; inch aur foot jaisi units ab bhi kuch log use karte hain. Aur padho length ki standard units mein.

Length sahi tareeke se naapna

Sahi device chuno: pencil ke liye 15-cm scale, kamre ki oonchaai ke liye metre scale ya measuring tape, aur ped ke tane ya chhaati ke naap ke liye darzi ke tape jaisa flexible tape. Scale ko cheez ke saath-saath, usse chhoota hua rakho, aur aankh theek us point ke upar rakho jise padh rahe ho. Agar scale ka sira toota ho, to kisi poore mark, jaise 1.0 cm, se shuru karo aur use ghatao: 1.0 cm se 10.4 cm tak ki cheez 10.4 cm − 1.0 cm = 9.4 cm lambi hai. Drishtiheen students ubhre hue nishaanon waali scale use karte hain jinhe chhookar mehsoos kar sakte hain.

Number, ek space aur unit likho, jaise 9.4 cm. Units ke naam aur symbols chhote akshar (lowercase) mein likhe jaate hain, symbols ke saath bahuvachan ke liye ‘s’ nahi lagta, aur symbol ke baad full stop nahi lagta, sirf vaakya ke ant mein. Mehraabon par lagi string lights jaisi ghumaavdaar line naapne ke liye flexible tape use karo, ya line ke saath dhaaga rakho, use seedha karo aur metre scale par naapo. Aur padho length sahi kaise naapein mein.

Position aur reference point

Deepa aur uske dost behas karte hain ki school paas hai ya garden, aur sab sahi hain, kyunki har koi apne ghar se naap raha hai. Agar sab ek hi jagah, jaise bus stand, se naapte, to sab ek hi baat kehte. Wo tay cheez ya jagah jahan se doori batayi jaati hai, reference point kehlaati hai. Sadak par ‘Delhi 70 km’ aur phir ‘Delhi 60 km’ likhe kilometre stones, Delhi ko reference point maankar bus ki position batate hain.

Motion aur rest

Koi cheez motion mein hai agar uski position reference point ke hisaab se samay ke saath badalti hai, aur rest mein hai agar nahi badalti. Reference point se farq padta hai: chalti bus mein baithe yaatri bus ke hisaab se rest mein hain, par bahar ki building ke hisaab se motion mein. Book ek sawaal poochhti hai: shaant samudra par seedhi line mein ek jaisi raftaar se chalta, bina khidki ka jahaaz ho, to kya tum bata sakte ho ki wo chal raha hai?

Motion ke types

• Linear motion: seedhi line mein, jaise oonchaai se giraaya rubber, farsh par dhakela gaya bhaari dabba, ya march-past mein students.
• Circular motion: gol raaste par, jaise dhaage se ghumaaya rubber ya merry-go-round.
• Oscillatory motion: ek tay jagah ke aage-peeche, jaise jhoola, dhaage se latka rubber, ya ek sira dabaakar chhodi gayi dhaatu ki patti.

Agar koi cheez ek tay samay ke baad apna raasta dohraaye, to uski motion periodic hai; circular aur oscillatory dono motion periodic hain. Aur padho motion ke types mein.

Har sawaal ka jawab Chapter 5 ke NCERT solutions mein hai.