Дан рычаг с различным количеством противовесов на каждой стороне. Массы противовесов m1=7кг и m3=78кг. Какова масса противовеса m2, если рычаг находится в равновесии?
в Британии и Америке. Выберите правильный вариант ответа А, В или С ( )
The most popular sport in Britain is football. Every large city has its own professional football team. Rugby is a fast, rough sport that is also very popular in Britain. The English play both rugby and football in the winter. In the summer they enjoy playing cricket.
British children are encouraged to take up a sport or a hobby in their free time. Popular indoor activities include collecting things such as model cars, coins, stamps or stickers of football players or pop stars. Other pastimes include birdwatching and train spotting.
Popular free-time activities for many British people are going to the cinema, theatre or a restaurant or watching TV or playing computer games.
In the USA the most popular sports are American football and baseball.
Americans play football in the winter months. Families attend games together or watch national games on TV. The annual championship called the “Superbow” is a national event. Baseball, on the other hand, is a summer sport. It is also the national sport of America.
American children collect things like the British. Baseball cards are popular collector's items as comics.
Other popular free-time activities are the same as for Britain such as being a member of a club or society, going to the cinema, eating out, visiting parks or museums, watching TV and surfing the net.
1.Most British people like football.
1) True 2) False 3) Not stated
2.Baseball is a winter sport.
1) True 2) False 3) Not stated
3.Girls play American football.
1) True 2) False 3) Not stated
4.Children collect things as a hobby.
1) True 2) False 3) Not stated
5. Both British and American like having meal at a cafe or a restaurant.
1) True 2) False 3) Not stated
2.Choose the right verb ( )
1) I ... this science fiction story recently.
a) read b) have read c) will read
2) Tomorrow they ... yellow and red leaves in the autumn forest.
a) collect b) will collect c) collected
3) Look! The children ... tennis outside.
a) play b) played c) are playing
4) She ... not decorate her room yesterday.
a) does b) will c) did
5) Every year he ... special presents for his nephews.
a) buys b) bought c) has bought
3. Complete the sentences, using tag- questions ( )
1) Allan went abroad last summer,…?
2) Her granny is fond of gardening,…?
3) My relatives will join them soon,…?
4) We haven't arranged the party yet,…?
4. Choose the correct word: tourists, consists of, birthplace, national, festival ( )***
1. London is the …… of many famous people
2.Every year twenty million ……. visit Great Britain.
3.The ….. flag of Great Britain is called the Union Jack.
4.The UK ……of four parts.
5.Edinburgh is famous for its annual ……. of Music and Drama.
Е=7,5 В, r= 0,5 Ом, R1=1,8 Ом,R2= 2 Ом,R3= 3Ом,R4=6 Ом
найти
I1 I2 I3 I4
U1 U2 U3 U4
решение
R2 || R3
1/R23 =1/R2 +1/R3 = 1/2 +1/3 = 5/6 ; R23 = 6/5 = 1.2 Ом
R123 = R1+R23 = 1.8+1.2 = 3 Ом
R123 || R4
1/R = 1/R123 + 1/R4 = 1/3 + 1/6 =3/6 = 1/2 ; R = 2 Ом
I = E / (R+r) = 7.5 / (2+0.5) = 7.5/2.5 = 3 A
U = R*I = 2*3 = 6 B
U123 = U4 = U = 6 B
I4 = U4/R4 =6/6 = 1 A
I1 = I123 = U123/R123 = 6/3 =2 A
U1 = I1*R1 = 2*1.8 =3.6 B
U2=U3 = U123 -U1 =6 - 3.6 = 2.4 B
I2 =U2/R2 = 2.4/2 =1.2 A
I3 =U3/R3 = 2.4/3 =0.8 A
ответ
I1=2A
I2=1.2A
I3=0.8A
I4=1A
U1=3.6B
U2= U3=2.4B
U4=6B
The most popular sport in Britain is football. Every large city has its own professional football team. Rugby is a fast, rough sport that is also very popular in Britain. The English play both rugby and football in the winter. In the summer they enjoy playing cricket.
British children are encouraged to take up a sport or a hobby in their free time. Popular indoor activities include collecting things such as model cars, coins, stamps or stickers of football players or pop stars. Other pastimes include birdwatching and train spotting.
Popular free-time activities for many British people are going to the cinema, theatre or a restaurant or watching TV or playing computer games.
In the USA the most popular sports are American football and baseball.
Americans play football in the winter months. Families attend games together or watch national games on TV. The annual championship called the “Superbow” is a national event. Baseball, on the other hand, is a summer sport. It is also the national sport of America.
American children collect things like the British. Baseball cards are popular collector's items as comics.
Other popular free-time activities are the same as for Britain such as being a member of a club or society, going to the cinema, eating out, visiting parks or museums, watching TV and surfing the net.
1.Most British people like football.
1) True 2) False 3) Not stated
2.Baseball is a winter sport.
1) True 2) False 3) Not stated
3.Girls play American football.
1) True 2) False 3) Not stated
4.Children collect things as a hobby.
1) True 2) False 3) Not stated
5. Both British and American like having meal at a cafe or a restaurant.
1) True 2) False 3) Not stated
2.Choose the right verb ( )
1) I ... this science fiction story recently.
a) read b) have read c) will read
2) Tomorrow they ... yellow and red leaves in the autumn forest.
a) collect b) will collect c) collected
3) Look! The children ... tennis outside.
a) play b) played c) are playing
4) She ... not decorate her room yesterday.
a) does b) will c) did
5) Every year he ... special presents for his nephews.
a) buys b) bought c) has bought
3. Complete the sentences, using tag- questions ( )
1) Allan went abroad last summer,…?
2) Her granny is fond of gardening,…?
3) My relatives will join them soon,…?
4) We haven't arranged the party yet,…?
4. Choose the correct word: tourists, consists of, birthplace, national, festival ( )***
1. London is the …… of many famous people
2.Every year twenty million ……. visit Great Britain.
3.The ….. flag of Great Britain is called the Union Jack.
4.The UK ……of four parts.
5.Edinburgh is famous for its annual ……. of Music and Drama.