Ishqalanish. Ishqalanish kuchi. Tabiatda va texnikada ishqalanish
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1. Sportchiga ta’sir etuvchi og‘irlik kuchi ish bajaradimi? Agar u: a) tramplinda tursa _______________________________________________ b) suvga tushayotganda ___________________________________________ c) suv yuziga ko‘tarilsa ____________________________________________ 2. Ishni joullarda ifodalang: A 1 = 2 MJ=______________ J; A 2 =10 kJ=______________ J; A 3 = 300 mJ=____________ J; A 4 = 12 µJ= ______________________ J. 2. Qanday hollarda tortish kuchi ish bajaradi (rasmga q)? 2. Avtomobil katta yo‘l bo‘ylab tekis harakatlanmoqda. Bunda og‘irlik kuchi ish bajaradimi? ______________________________________________________ 3. Qaysi holatda ko‘p ish bajariladi: jismni 5 m masofaga 8 N kuch ta’sirida ko‘chirishda yoki 2 m masofaa 20 N kuch ta’sirida ko‘chirishda? Ikkala holatda ham kuchlar harakat yo‘nalishida ta’sir qiladi. ______________________________________________________________ 4. Og‘irligi har xil bo‘lgan ikki qiz bir vaqtning o‘zida uyning ikkinchi qavatiga zinadan yugurishdi. Ular bir vaqtning o‘zida bir xil kuch sarfladimi? ______________________________________________________________ ______________________________________________________________ 5. Kim ko‘proq kuch sarflaydi: zinapoyadan asta-sekin ko‘tarilgan odammi yoki bir xil balandlikdagi tayanchli sakrashni amalga oshiradigan bir xil massadagi sportchimi (230-rasm)? ______________________________________________________________ ______________________________________________________________ 6. Bir xil o‘lchamdagi va dizayndagi ikkita kema turli kuchlar ta’sir qiladi. Bu kemalar bir xil tezlikda harakat qiladimi? ______________________________________________________________ ______________________________________________________________ 7. Quyidagi holatlarda, m=2 kg massali toshga ta’sir qiluvchi og‘irlik kuchi qancha ish bajaradi: a) u h = 5 m balandlikdan tushganda? _______________________________ ______________________________________________________________ b) u h = 5 m masofaga ko‘tarilganda? _______________________________ ______________________________________________________________ 8. Traktor botib qolgan avtomobilni tortib, s=10 m masofaga sudrab bordi. Shatakka oluvchi trosning taranglik kuchi A=140 kJ ish bajardi. Bu kuchning qiymatini aniqlang. ______________________________________________________________ ______________________________________________________________ 9. Agar aravaga ta’sir qiluvchi o‘zgarmas F=100 N kuch A=2 kJ ish bajarsa, u qancha masofani o‘tadi? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 10. m=10 kg massali suvli chelak h=1 m masofaga ko‘tarilganda trosning elastiklik kuchi A=120 J ish bajardi. Chelak tekis ko‘tarilyaptimi? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 11. Avtomobil tezlashganda, unga qo‘yilgan teng ta’sir etuvchi kuch A=100 kJ ish bajardi. Avtomobilni dvigateli o‘chgan holatda s=50 m masofada to‘xtatish uchun tormoz kuchi qancha bo‘lishi kerak? Qaysi kuchlar ish bajarmadi? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 12. Massasi m=80 kg bo‘lgan raketa qandaydir balandlikka vertikal ko‘tarilganda, F=1,2 kN tortuvchi kuch A=120 kJ ish bajardi. Raketa qanday balandlikka ko‘tarilgan? Ko‘tarilish vaqtida og‘irlik kuchi va raketaga qo‘yilgan teng ta’sir etuvchi kuch qancha ish bajargan? Raketa massasining o‘zgarishini hisobga olmang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 13. Massasi 4 kg tosh 5 m balandlikdan tushadi.Tosh tushish paytida qanday kuch musbat ish bajaradi? Bu ishni hisoblang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 14. Bola velosipedni haydash uchun, gorizontal yo‘nalishda 40 N kuch bilan ta’sir qiladi. Bu holda velosiped tekis harakatlanadi. Agar bola 5 daqiqada 12 kJ ishni bajargan bo‘lsa, velosiped tezligini aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 15. Lift yordamida bir necha kishini 20 m ga olib chiqish uchun 42 kJ ish bajarildi. Liftda nechta odam olib chiqildi? Ularning har birining og‘irligini 700 N ga teng deb hisoblash mumkin? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 16. Aravaga ot 400 N kuch bilan ta’sir qilib, 0,8 m/s o‘zgarmas tezlikda aravani tortadi. Ot 2 soat ichida qanday ishni bajaradi? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 17. Agar tortish kuchi 50 kN bo‘lgan poyezd o‘rtacha 54 km/h tezlik bilan harakatlanib 2 soat ichida poyezd qancha ish bajarganligini aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 18. Massasi 100 kg bo‘lgan yuk pol bo‘ylab qanday masofaga ko‘chirilsa, unga qo‘yilgan gorizontal kuch 4,5 kJ ish bajaradi? Yuk va pol orasidagi ishqalanish koeffitsienti 0,15 ga teng. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 19. Kishi chuqur quduqdan bir chelak suv tortmoqda. Arqonni 25 cm/s tezlikda harakatlantirsa, u 1 minutda qanday ishni bajaradi? Bir chelak suvning massasi 10 kg. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 20. Kishi aravachani gorizontal ravishda 60 N kuch bilan itaradi. Bunda aravacha tekis harakatlanadi. Agar odam 3 minutda 14 kJ ish bajarsa, aravachaning tezligi aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 21. Aravacha 300 N gorizontal kuch bilan harakatga keltiriladi. Buda aravacha tekis harakatlanadi. Agar 20 minutda 180 kJ ish bajarilgan bo‘lsa, uning harakat tezligi aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 22. Ot og‘irligi 300 kg bo‘lgan chanani 2 m/s o‘zgarmas tezlik bilan tortmoqda. Agar ot 1 soat ichida chanani ko‘chirish uchun 2,2 MJ ish bajarilgan bo‘lsa, chana va yo‘l orasidagi ishqalanish koeffitsientini aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 23. Prujinani 10 cm ga cho‘zish uchun 100 N kuch ta’sir qilish kerak. Prujinani cho‘zish uchun qanday ish bajarildi? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 24. Prujina 1 cm ga uzaytirildi, prujina yana 1 cm ga cho‘zildi. Bu holatlarning qaysi biri ko‘proq ish bajarildi? Qanchalik katta? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 25. 4 cm qalinlikdagi taxtaga 10 cm uzunlikdagi mix oxirigacha qoqildi. Agar mixni taxtaga kirgizish uchun 20 N kuch ta’sir qilgan bo‘lsa, mixni sug‘urib (tortib) olish uchun qanday ish bajarish kerak. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 26. Grafikda betonni ko‘chiruvchi kuchlarning yo‘lga bog‘liqligi ko‘rsatilgan (rasmga.q). Kuchlardan qaysi biri katta ish bajargan? Necha marta? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ Download 1.87 Mb. Do'stlaringiz bilan baham: 
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