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

5-Mavzu: Kinetik energiya
1.Quyidagi javoblar orasidan kinetic energiya formulasini toping.
+a) E_k=m𝑣²/2 b)E_k=mgh c) E_k=mgh/2 d) E_k= mg
2.Muz ustidagi 40g massali xakkey shaybasiga zarb bilan urganda 25m/s tezlikka erishdi.Shaybaga qanday kinetic energiyaga erishgan?
a)12J + b)12.5J c)25J d)50J
3.72km/soat tezlik bilan ketayotgan massasi 1.2tonnali avtomabilni toxtatish uchun qancha ish bajarish kerak?
a)120kJ b)200kJ c)60kJ +d)240kJ
4.10 m/s tezlik bilan ketayotgan velosiped tezligini 20 m/s ga qadar oshirishi uchun qanday ish bajarishi kerak?Velosipedning haydovchi bilan massi 100 kg gat eng.
a)5kJ b)20kJ + c)10kJ d)15kJ
5.72 km/soat tezlik bilan ketayotgan massisi 200t li poyezd tezligini 144km/soat ga qadar oshirish uchun elektravoz qancha ish bajarishi kerak(MJ)?
+a)120 b)40 c)30 d)160
6.7.7km/s tezlik uchayotgan Yerning suniy yoldoshi 40000MJ kinetic energiyaga ega.Suniy yoldoshning massisini toping(kg).
a)1630 +b)1349 c)1432 d)1512
7.Boshlangich tezligi 36km/soat bo’lganda 2t li avtomabilning kinetic energiyasi qancha boladi(kJ).
a)50 +b)100 c)150 d)30
8.15 m/s tezlik bilan ketayotgan velosiped tezligini 20 m/s ga qadar oshirishi uchun qanday ish bajarishi kerak?Velosipedning haydovchi bilan massi 100 kg ga teng.
a)5kJ b)20kJ + c)8750J d)1500J
9.72 km/soat tezlik bilan ketayotgan massisi 100t li poyezd tezligini 144km/soat ga qadar oshirish uchun elektravoz qancha ish bajarishi kerak(MJ)?
+a)60 b)40 c)30 d)160
10.Agar 8kg massali jismning impulse 8kg*m/s bolsa uning kinetik energiyasini toping.
a)8 b)12 c)16 +d)4