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

Yechish:

1. 
   v=const. F=kmg N=Fv = kmgv =10·1000·9.8·0.07= 6.9 kW;
   
2. 
   F=mgsinα+ F=mg( )
   

= =0.05 = 0.998

N= mgv( )= 1000·9.8·10(0.07·0.998 + 0.05)=11.8 kW;

3. 
   F= - mgsinα F=mg( )
   

N= mgv( )=2 kW

49. Og’irligi 1 T bo’lgan avtomobil tog’dan matori o’chirilgan holda 53 km/soat o’zgarmas tezlik bilan tushmoqda. Tog’ har 100 m yo’lda 4m balandlikka ko’tarilgan qiyalikka ega. Shu tog’ning o’ziga o’shanday tezlik bilan ko’tarilish uchun avtomobilning dvigateli qanday quvvatga ega bo’lishi kerak.

Yechish:

=mgsinα =kmgcosα mgsinα = kmgcosα k=tgα;

= +mg·sin ; =mg(kcosα + sinα);

v=mgv(kcosα + sinα)= mgv(tgα·cosα + sinα)=2mgvsinα=2mgv =11.8 kW;

50. 5 kg massali miltiqdan 5* kg massali o’q 600 m/s tezlik bilan otilib chiqadi. Miltiqning orqaga tepish tezligi topilsin.

Yechish:

- =0 = = = 0.6 m/s