Ishqalanish. Ishqalanish kuchi. Tabiatda va texnikada ishqalanish
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Mexanikaning “Oltin qoidasi”
1. Qanday ishga foydali ish deyiladi, qanday ishga esa to‘liq ish? ______________________________________________________________ ______________________________________________________________ 2. Agar mexanizmning tugunlaridagi ishqalanish kamaytirilsa, FIK qanday o‘zgaradi? ______________________________________________________________ ______________________________________________________________ 3. Nima uchun FIK 100 % ga teng bo‘lgan mashinani yaratish imkonsiz? ______________________________________________________________ ______________________________________________________________ 4. Kran dvigateli jami 1 kJ ish bajaradi. Dvigatelning foydali ishi quyidagilardan qaysi biriga teng bo‘lishi mumkin? a) 1530 J; b) 1000 J; c) 900 J. ______________________________________________________________ ______________________________________________________________ 5. Oddiy mexanizm yordamida 120 J foydali ish bajarildi. Umumiy ish 150 J bo‘lsa, mexanizmning FIK ni aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 6. Jism qiya tekislik bo‘ylab ko‘tarilib, 180 kJ foydali ishni bajaradi. Qiya tekislikning FIK i 90% bo‘lsa, umumiy ishni aniqlang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 7. Jism 50 N kuch ta’sirida qiya tekislik bo‘ylab ko‘tarildi. Agar qiya tekislikning uzunligi 2 m, balandligi 50 cm va FIK i 80% bo‘lsa, jismning massasini toping. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 8. Massasi 45 kg bo‘lgan yuk qo‘zg‘luvchan va qo‘zg‘almas bloklardan tashkil topgan qurilma yordamida ko‘tariladi (rasmga qarang). Qurilmaning FIK i 75% bo‘lsa, arqonning ikkinchi uchiga qanday kuch qo‘yilishi kerak? 9. Richagning qisqa yelkasiga (rasmga qarang) og‘irligi 1200 N bo‘lgan yuk osilgan. Richagning uzun yelkasiga 360 N kuch qo‘yilib, yuk 0,12 m yuqoriga tekis ko‘tarildi. Bunda harakatlantiruvchi kuchning qo‘yilish nuqtasi 0,5 m ko‘tarildi. Richagning FIK ni hisoblang. 10. Richagning uzun yelkasiga 500 N kuch qo‘yilib, massasi 245 kg bo‘lgan yuk 6 sm yukoriga tekis ko‘tarildi, bunda kuchning qo‘yilish nuqtasi 0,3 m pastga tushdi. Richagning FIK ni hisoblang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 11. Agar har bir blokdagi ishqalanish bir xil bo‘lsa, og‘irligi teng bo‘lgan yuklarni ko‘tarishda ko‘zg‘almas bloklar sistemasining qaysinisida FIK katga bo‘ladi? Javobingizni asoslab bering. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 12. Bloklardan foydalanib P yukni ayni bir balandlikka ko‘tarish mumkin (rasmga.q) Ularda bloklar massasi va ishqalanish bir xil. Qurilmaning FIK bir xil buladimi? Javobingizni asoslab bering. 13. Arqonga 250 N kuch bilan ta’sir qilib, qo‘zg‘almas blok yordamida massasi 24,5 kg bo‘lgan qumli chelak 10 m balandlikka ko‘tarildi. Qurilmaning FIK ni hisoblang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 14. Arqonga 360 N kuch bilan ta’sir qilib, qo‘zg‘aluvchan blok yordamida massasi 54 kg bo‘lgan mixli yashik qurilayotgan binoning beshinchi qavatiga ko‘tarildi. Qurilmaning FIK ni hisoblang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 15. Yuk bloklar yordamida tekis ko‘tarildi (rasmga.q) Rasmda berilganlardan foydalanib, qurilmaning FIK ni hisoblang. 16. O‘quvchi og‘irligi 12 N yukning uzunligi 0,8 m, balandligi 0,2 bo‘lgan qiya tekislik uchiga tskis chiqardi. Bunda kiya tekislik uzunligiga parallel yo‘nalgan kuchning ko‘chishi 5,4 N ga teng. O‘quvchi qurilmaning FIK ni hisoblashda qanday natija olishi kerak? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 17. Qiya tekislik bo‘ylab massasi 15 kg yukni tekis chiqarishda yukka bog‘langan dinamomstr 40 N kuchni ko‘rsatdi. Agar qiya tekislikning uzunligi 1,8 m, balandligi 30 cm bo‘lsa, qiya gekisliknmng FIK ni hisoblaig. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 18 * . Rasmda ko‘rsatilgan bloklar sistemasi yordamida yuk ko‘tariladi. Har bir blokning FIK i 90% ni tashkil qiladi. Sistemaning FIK ni toping. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 19. Birinchi yukni ko‘tarishda qo‘zg‘aluvchi blokning FIK i 80%, ikkinchi yukni ko‘tarishda esa 90% ni tashkil qiladi. Qaysi yuk kattaroq? Necha marta katta? Blokdagi ishqalanishni hisobga olmang. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ 20. Nasosi dvigatelining quvvati 5 kW, FIK i 70% bo‘lsa, 36 m chuqurlikdagi quduqdan 1 soatda qancha suv chiqarish mumkin? ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ Qo‘shimcha ma’lumot manbalaridan foydalangan holda ba’zi mexanizmlarning FIK i va ular bajaradigan ishi haqida bilib oling. Topgan ma’lumotlaringizfan foydalanib 1-2 ta masala tuzing, ularni yeching. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ Download 1.87 Mb. Do'stlaringiz bilan baham: 
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