Вопрос школьника по предмету Физика
Амплитуда колебаний 80 мм, период 12 с, записать уравнение движения
Ответ учителя по предмету Физика
xm= 80мм= 0.08м
Цикллическая частота
w= 2пи/ Т= 2пи/12= пи/ 6
Уравнение
И через синус и через косинус
x= xm sin wt
x= 0.08 sin пиt/6
или
x= xm cos wt
x= 0.08 cos пиt/6
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for i:=1 to n do begin
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write(‘ a[‘,i,’,’,j,’]=’);
read (a[i][j]);
writeln; end;
end;end;
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Выберите правильный вариант.
1. Where … your husband … five years ago?
a) did… work b) do … work c) does … work
2. I have … car. … car is white. My … friend has no … car.
a) the, —, the, — b) a, the, a, — c). a, the, —,—
3. For breakfast she … a sandwich and a cup of tea.
a) to have b) have c) has
4. I (to write) an English exercise now.
a) write b) am writing c) is writing
5. The park gates … at 6.30 p.m. every evening.
a) were locked b) will be locked c) are locked
6. …. is collecting stamps.
a) my friend’s hobby b) my hobby’s friend c) my friends’s hobby
7. … you … me at the railway station next Sunday?
a) Will … meet b) Shall … meet c) Do … meet
8. The weather (to change), and we can go for a walk.
a) changed b) have changed c) has changed
9. You … a good friend.
a) is b) are c) am
10. My … parents are my grandparents.
a) sister’s b) mother’s c) friend’s
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a) received b) was received c) were receive
12. I usually go to …college by … bus.
a) the, a b) —, the c) —, —
13. Bread … every day.
a) are eaten b) is eaten c) eat
14. I live in Moscow but … family lives in London.
a) his b) their c) my
15. You (to be) good friends.
a) am b) are c) is
16.…you … home at six o’clock yesterday?
a) Do …come b) Did…come c) Does… come
17. I (not to eat) ice cream tomorrow.
a) not eat b) don’t eat c) won’t eat
18. Nick … to Moscow next week.
a) is sent b) will be sent c) was sent
19. Mary (to buy) a new hat.
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a) will be finished b) was finished c) will finish
21. My…sister’s children study in …USA.
a) the, the b) —, the c) —, —
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a) speaks b) to speak c) speak
23. My friends (not to do) their homework at seven o’clock yesterday.
a) wasn’t doing b) didn’t do c) weren’t doing
24. She … English two years ago.
a) studyed b) studies c) studied
25. My friends (not to do) their homework now.
a) isn’t doing b)aren’t doing c) don’t do
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a) founded b) was founded c) were founded
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a) —, a, — b) the, the, the c) —, the, the
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a) has b) to have c) have
29. They … tea every day.
a) drinks b) drank c) drink
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a) go b) goes c) went
31. This text … at the last lesson.
a) translated b) will be translated c) was translated
32. We … to a concert last Saturday.
a) were invited b) are invited c) invited
33. I … to the cinema on Sunday.
a) go b) will go c) goes
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a) our b) their c) his
35..My dad asked me to buy ….
a) today’s newspaper b) today newspaper c) newspaper’s today
36. She was … first woman to swim across … English Channel.
a) a, the b) —, — c) the, the
37. When … they … home?
a) did return b) have returned c) do returned
38. Helen … this book 4 times.
a) read b) have read c) has read
39. When the phone rang, I… dinner.
a) cook b) was cooking c) cooked
40. Safari parks are … places of all to keep animals.
a) better b) the best c) more better