Англиский язык NORMAL LIFE Prince William is the grandson
Queen Elizabeth Il and
the eldest son of Prince Charles and Princess Diana. He and
his wife, Kate, live in a large apartment in Kensington Palace in
London with their two young children, George and Charlotte.
They also have a home in Norfolk in the east of England.
William works hard but he
got a normal job. Instead,
he has a lot of royal duties: he meets foreign kings, queens and
presidents and he helps a lot of different charities. He is famous all around the
world, but he
want his home life to be special or different.
Kate also has a lot of royal duties. But like her husband, she
a normal life
too. She goes shopping in the local supermarket, and she sometimes meets friends
and has coffee with them. She always buys her own clothes. Sometimes she buys
expensive designer clothes, but she often goes
normal clothes shops.
1 SPEAKING Look at the photos. Which members of the
British Royal Family can you name?
2 USE OF ENGLISH Read the magazine article and complete
the gaps with one of the words below.
of
2 a isn't
doesn't
4 a want
5 a for
6 a of
b for
c with
b hasn't c doesn't
b does
c isn't
b wants c doesn'twant
b in
c to
b at
c by
William and Kate
are happy together
and they love their
apartment in London
and their quiet home
in the country. Kate's
hobbies are cooking,
walking their dog Lupo
and playing with her
children. William and
Kate are proud
their young children.
They think they have got a wonderful family! Люд минутыы
Данные пробирки имеют одинаковую частоту вращения, но разные линейные скорости, так как одна пробирка находится дальше другой от центра центрифуги. Пусть r₁ = R – радиус окружности, описываемый первой пробиркой, тогда r₂ = (R - 11) – это радиус окружности, по какой движется вторая пробиркой. Циклические частоты пробирок одинаковы ⇒ ω₁ = ω₂, а линейные скорости по условию равны: v₁ = 56 м/с, v₂ = 34 м/с
По формуле из кинематики: v₁ = ω₁·r₁, v₂ = ω₂·r₂ ⇒ ω₁ = v₁/r₁ = ω₂ = v₂/r₂ ⇒ v₁/R = v₂/(R - 11) ⇒ (по правилу пропорции) v₁ · (R - 11) = v₂ · R ⇒
R · (v₁ - v₂) = 11 · v₁ ⇒ R =
сантиметров
ответ: первая пробирка описывает окружность радиусом в 28 см.
Объяснение:
Дано:
a = 20 м/с²
L = 2 км = 2 000 м
t = 10 c
V₀ - ?
1)
За 10 секунд ракета поднимется на высоту:
H = a·t² / 2 = 20·10² / 2 = 1000 м
2)
Теперь запишем уравнения движения снаряда:
x = (V₀·cos α)·t
y = (V₀·sin α)·t - g·t² / 2
3)
Учтем, что
L = x
2 000 = (V₀·cos α)·10
V₀·cos α = 200 (1)
4)
Снаряд попадет в ракету, если:
H = y
H = (V₀·sin α)·t - g·t² / 2
1000 = (V₀·sin α)·10 - 10·10² / 2
100 = (V₀·sin α) - 50
V₀·sin α = 50 (2)
Разделим уравнение (2) на уравнение (1):
tg α = 50 / 200 = 0,25
Угол :
α ≈ 14°
Тогда из (2)
V₀ = 50 / sin α = 50 / sin 14° = 50 / 0,24 ≈ 210 м/с