7-sinf Fizika IV chorak uchun mavzulashtirilgan testlar 1-Mavzu: Reaktiv harakat. Raketaning tuzilishi va ishlashi

8-Mavzu: Masalalar yechish
1.Massasi 2kg bo`lgan jism 20 m/s tezlik bilan gorizontal otildi. 2s dan keyin uning kinetik energiyasi nimaga teng bo`ladi(J)?
a) 200 b) 400 +c) 0 d) 2600
2. Agar jismning kinetik energiyasi 1J, impulse 1kg* m/s bo`lsa, uning massasi qancha(kg)?
a) 0,25 b) 1 c) 2 +d) 0,5
3. Uchib ketayotgan raketaning har sekundda 20 kg gaz 450 m/s tezlik bilan otilib chiqayotgan bo`lsa, reaktiv kuch nimaga teng bo`ladi(kN)?
a)4,5 b) 6,5 +c) 9 d) 12
4. Og`irligi 50N bo`lgan chana muz ustida 8m ga siljiydi. Og`irlik kuchini bu yo`ldagi ishini toping(J).
a)100 +b) 400 c) 40 d)0
5.Shtangachi massasi 170 kg bo’lgan shtangani 1,8m balandlikka dast ko’targanda qancha ish bajariladi?
a)120J b)180J c)2,4kJ +d)3,06kJ
6. Ma`lun tezlik bilan harakatlanayotgan jism impulsi 10 kg*m/s, kinetic energiyasi 50J. Jismning tezligi va massasini toping.
+a) 10m/s, 1kg b) 20m/s, 1kg c) 15m/s, 2kg d) 10m/s, 4kg
7. Bikrligi 10000N/m bo`lgan prujina muvozanat holatdan 8 sm masofaga cho`zildi. Shu holatda prujinaning potensial energiyasi nimaga teng bo`ladi (J)?
a) 64 +b) 32 c) 128 d ) 16
8. Bikrligi 4000N/m bo`lgan prujina muvozanat holatdan 6 sm masofaga cho`zildi. Shu holatda prujinaning potensial energiyasi nimaga teng bo`ladi (J)?
a) 3,8 b) 3 +c) 7,2 d) 1,8
9. Prujinani 5mm cho`zish uchun 3kJ ish bajarish kerak. Shu prujinani 1,2 sm ga cho`zish uchun qancha ish bajarish kerak bo`ladi(kJ)?
+a) 34,5 b) 38 c) 28,6 d) 16,4
10. Prujinani 3sm cho`zish uchun 6kJ ish bajarish kerak. Shu prujinani 4 sm ga cho`zish uchun qancha ish bajarish kerak bo`ladi(kJ)?
a) 12 +b) 21,3 c) 22 d) 18