Di-11-19-guruh talabasi Xudoyqulov Abdug’ani 1 ϑ=600 m/s tezlik bilan uchayotgan m 65·10

Yechish:

mgh = + F kglcosα=

1. 
   k= = 0.22
   
2. 
   Q=Fl = kmglcosα = 5.7 J
   

47. 2T massali avtomobil har 100 m yo’lda 4m balandlikka ko’tariladigan toqqa chimoqda. Ishqalanish koefitsiyenti 0.08 ga teng. Avtomobil dvigatelining 1) 3 km yo’l yurgandagi bajargan ishini 2) shu yo’lni 4 min da bosib o’tsa quvvatini toping.

Yechish:

F=mg(kcosα + ) = = 0.04; = 0.999;

1. 
   A = Fs = mgs(kcosα + ) = 2000·9.8·100(0.08·0.999 + 0.04) = 7 MJ
   
2. 
   N= = = 29.2 kW;
   

48. 36 km/soat o’zgarmas tezlik bilan ketayotgan 1 T massali avtomobil dvigatelining 1) gorizontal yo’lda ketayotganda, 2) har 100 km yo’lda 5 m balandlikka ko’tarilayotgan toqqa chiqayotganda 3) shu qiyalikdagi tog’dan tushayotganda qanday quvvatga ega bo’lishi topilsin. Ishqalanish koefitsiyenti 0.07 ga teng.