Fizik a fizik a

J a v o b:

• Agar g’o’laning massasi boltaning massasidan katta bo’lsa, boltaning orqasi bilan urgan ma’qul, agar aksincha bo’lsa, q’o’lani urgan ma’qul.

M a s a l a № 2

• Kosmik kema erkin uchayotganda fazogir qo’lidan massiv buyumni qo’yib yuborsa (itarmay yoki turtib yubormay), fazogirga nima bo’ladi ? Agar u buyumni otib yuborsachi?

J a v o b:

• Agar fazogir qo’lidan buyumni chiqarib yuborsa, unda uning kemaga nisbatan vaziyati o’zgarmaydi; agar otib yuborsa, unda fazogir ham harakatga keladi.

2 - s a v o l :

• Dvigateli o’chirilgan avto-mobil gorizontal yo’lda tekis harakatlana oladimi ?
• J a v o b :
• Dvigateli o’chirilgan avtomobil gorizontal yo’lda tekis harakat-lana olmaydi, chunki bunda shossega ishqalanishni va havoning qarshiligini hech narsa kompensatsiyalamaydi.

M a s a l a № 7

• B e r i l g a n :
• m = 2 kg
• F = 60 N
• t=5s
• _________________________________ a=? v-=? S=?

• Y e c h i s h:
• a = F/m = 60 / 2 = 30 m/s2
• v = at = 30 . 5 = 150 m/s
• S = at2 / 2 = 30.52 / 2 = 375 m

• Massasi 2 kg bo’lgan tinch turgan jismga 5 s davomida 60 N kuch ta’sir qilgan bo’lsa, jismning olgan tezlanishi, shu vaqtda erishgan tezligi va o’tgan yo’li topilsin.

Tajriba - masala №4

• Elektron tarozi va shtangentsir
• kul yordamida berilgan jismning
• zichligini toping.

Tajriba - masala №6

• Menzurka, elektron tarozi yordamida jismning zichligini toping.

2 – T E S T

• 30 m/s boshlang’ich tezlik bilan erkin tushayotgan jismning harakat bosidan 5 s o’tgan paytdagi tezligi necha m/s bo’ladi ? ( g=10 m/s2)
• A) 35 ; B) 45 ; C) 60 ;
• D) 80 ; E) 90 ;

3 - TEST

• Momaqaldiroq vaqtida odam chaqmoq chaqqandan keyin
• 15 s o’tgach, momaqaldiroqning gumburlagan tovushini eshitdi. Undan qancha masofa narida chaqmoq chaqqan ?
• Tovushning havodagi tezligi 340 m/s
• A) 2 km ; C) 5 km
• B) 3 km ; D) 7 km
• E) 9 km

J a v o b l a r :

• 1 - Test : E) 1000
• 2 - Test : D) 80
• 3 - Test : C) 5 km

Uy vazifasi :

• A.P.Rimkevich «Fizikadan masalalar to’plami»
• № 665 - 675 (Toqlari) masalalarni bajarish.

M a s a l a № 1

• B e r i l g a n :
• l0 = 8 m
• S = 0,8 sm2 = 0,8 . 10 -4 m2
• m = 200 kg
• E = 200 GPa = 200 . 109 Pa
• ∆ l = ?

• Y e c h i s h :
• δ = F / S ; δ = E ε = E ∆l / l0 ;
• E ∆l / l0 = F / S ;
• ∆l = l0 . m . g / E . S
• ∆l =8.200.10/200.109.0,8.10-4=
• = 1 . 10 -3 m = 1 mm.

• Uzunligi 8 m, ko’ndalang kesimining yuzi 0,8 sm2 bo’lgan po’lat tayoqchaga 200 kg massali yuk osil-gan bo’lsa, u qanchaga cho’ziladi? Po’lat uchun Yung moduli 200 GPa.

M a s a l a № 2

• B e r i l g a n :
• m = 2000 kg ;
• a = 0,8 m/s2 ;
• k = 100 kN/m=1.105 N/m
• _______________________
• ∆ l = ?

• Y e c h i s h :
• F = Fel ;
• F = ma ; Fel = - k . ∆l ;
• ma = - k . ∆l ;
• ∆l = m a / k ;
• ∆l = 2000 . 0,8 / 1.105 =
• = 16 . 10 -3 m = 16 mm.

• Massasi 2000 kg bo’igan avtomobilning 0,8m/s2 tezlanish bilan shatakka oilb ketilayotganda trosning cho’zilishini toping. Trosning bikrlik koeffitsiyenti 100 kN/m ga teng.