Вопрос школьника по предмету Физика
ПОЖАЛУЙСТА ОТВЕТЬТЕ НА 3 ВОПРОСА
ФИЗИКА, 7 КЛАСС
1. Какую работу называют полезной?
2. Какую работу называют затраченной?
3. Почему полезная работа меньше затраченной?
Ответ учителя по предмету Физика
Ответ:
Объяснение:
Работа совершенная только по отношению к рабочему телу Без учета трат и работы на силу трения и орудия совершения полезной работы
Коэффициент полезного действия КПД это отношение полезная работа совершенная механизмом Ко всей затраченной работе подведенной энергии за то же время
Потому что трение и другие потери энергии полностью исключить невозможно
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Заранее спасибо.
Jessica is twelve years old and she lives in London. She goes to a secondary school and she’s in class eight. Her favourite subjects are Geography and Maths. She likes Science too. She isn’t fond of French and History.
She goes to school with her friend by bus. They meet at the bus stop at quarter past eight. School lessons start at quarter to nine and finish at half past three. After school she goes home and does her homework. Then she spends time with her friends in the park. They play volleyball or rollerblade there. In the evening Jessica watches TV. She practices the clarinet, too.
On Wednesdays she doesn’t go home at half past three. She plays table tennis in the school gym. She isn’t very good at it, but it’s fun. She likes sport. On Saturday mornings Jessica has a clarinet lesson. Then she usually plays cricket with her friends in the garden.
Jessica has got a brother. His name’s Cameron. He’s ten. He goes to a primary school. He walks to school. His classes start at nine o’clock, so Cameron leaves home at ten to nine. He also likes sport. On Tuesday and Friday afternoons he has karate classes. They start at half past five and last for an hour and fifteen minutes.
1. Jessica starts school at …
1. a) quarter past nine
c) quarter to nine
2. b) half past nine
d) quarter past eight
2. Jessica needs about … to get to school.
1. a) half an hour
c) ten minutes
2. b) one hour
d) ninety minutes
3. Jessica doesn’t like … at school.
1. a) Maths
c) French
2. b) Geography
d) Science
4. Jessica goes … with fiends in the park.
1. a) to play tennis
c) to ride a bike
2. b) to play table tennis
d) to rollerblade
5. Cameron is … years old.
1. a) 8
c) 12
2. b) 10
d) 13
6. Cameron does karate … .
1. a) at the weekend
c) every Wednesday
2. b) once a week
d) twice a week
7. Cameron’s karate class finishes at … .
1. a) six thirty
c) half past six
2. b) quarter to seven
d) quarter past seven
1.
2. Choose the true sentence.
1. Jessica goes to a primary school in London.
2. Jessica does her homework when she comes back from the park.
3. Jessica plays a musical instrument at the weekend.
4. Jessica is very good at playing table tennis.
3. Fill in the blanks with “who”, “what’, “when”, “when”, “where”, “why”. Use each word only once.
1. — _________does Jessica usually go for a walk? — In the park.
2. — _________does Cameron leave home for school? — At ten to nine.
3. — _________does the girl usually do in the park? — She rollerblades there.
4. — _________do Jess and her friend meet at the bus stop? — At quarter past eight.
5. — _________doesn’t she go home later on Wednesdays? — Because she plays table tennis.
6. — _________likes sport? — Jess’s little brother does.
1) their first child…in Parts.(bring up)
2) ice hockey … In Canada (play)
3)the money … In the safe(keep)
Раскройте скобки чтобы получились предложения в страдательном времени страдательного залога
1)your credit card … On the floor(find)
2)the monuments …in 1943(ruin)
3)a big bunch of flowers…for her birthday(send)