nhiều nhưng mong vẫn đc giúp
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1 taking
2 comedian
3 organizing
4 poet
5 musician
6 designed
7 taking
8 opera
Ex6
1 B
2 A
3 C
4 D
5 C
6 A
7 D
8 A
9 C
1 as exciting as action film
2 the same as Salvador's
3 as well as my sister
4 the same
5 as long as we thought at first
Ex11
1 D
2 D
3 D
4 D
Tờ 1
41 It's very important to use body language in communication
42 Despite her age, she still leads an active life
43 My mother said that you had to decorate the room carefully
44 People recycle old cans to make new ones
45 Tim is always forgetting his homework
46 T
47 F
48 T
49 T
50 F
Tờ 2
17 C => hard
18 do => make
19 D => has
20 to go => going
21 A => At
22 B => to
23 C => beautifully
24 D => five-star
25 is => was
V
26 would travel
27 be
28 to buy
29 has spoken
30 Has - just been finished
VI
31 for
32 as
33 about
34 with
35 than
VII
36 development
37 exploration
38 behavior
39 deforestation
40 specialness
Lam ơi!!!!!!!!!!!!!!
Mấy câu tui hỏi mới là mấy câu chính. Cô cho tụi tui ghi vậy mà
1. Yes it is
2.Chung cake was invented by Prince Lang Lieu
3.Viet Nam
4.0 hiểu :v
5.The cake is boiled for about 12 hours
Bài 1.
Cơ năng ban đầu:
\(W=\dfrac{1}{2}mv^2+\dfrac{1}{2}kx_0^2=0+\dfrac{1}{2}\cdot200\cdot0,5^2=25J\)
a)Cơ năng tại nơi lò xo dãn 30cm:
\(W'=\dfrac{1}{2}mv'^2+\dfrac{1}{2}kx^2=\dfrac{1}{2}\cdot0,2\cdot v'^2+\dfrac{1}{2}\cdot200\cdot0,3^2\)
\(=0,1v'^2+9\left(J\right)\)
Bảo toàn cơ năng: \(W=W'\)
\(\Rightarrow0,1v'^2+9=25\Rightarrow v'^2=160\)
\(\Rightarrow v=4\sqrt{10}\)m/s
b)Cơ năng tại nơi \(W_đ=2W_t\):
\(W'=W_đ+W_t=3W_t=mgz\left(J\right)\)
Bảo toàn cơ năng: \(W=W'\)
\(\Rightarrow25=3mgz\Rightarrow z=4,167m\)
Bài 2.
\(v=54\)km/h=15m/s
Cơ năng ban đầu:
\(W=\dfrac{1}{2}mv^2=\dfrac{1}{2}\cdot1\cdot15^2=112,5J\)
a)Cơ năng tại nơi có độ cao cực đại:
\(W'=mgh_{max}\)
Bảo toàn cơ năng: \(W=W'\)
\(\Rightarrow112,5=mgh_{max}\Rightarrow h_{max}=11,25m\)
b)Cơ năng tại nơi \(W_đ=3W_t\Rightarrow W_t=\dfrac{1}{3}W_đ\):
\(W'=W_đ+W_t=\dfrac{4}{3}W_đ=\dfrac{4}{3}\cdot\dfrac{1}{2}mv'^2=\dfrac{2}{3}mv'^2\)
Bảo toàn cơ năng: \(W=W'\)
\(\Rightarrow112,5=\dfrac{2}{3}mv'^2\Rightarrow v'\approx13\)m/s