Giúp em với ạ cảm ơn nhiều ạ
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Những câu hỏi liên quan
TH
3 tháng 10 2021
21. am doing - think - know
22. buys
23. rains - is raining
24. is cooking - cooks
DT
Đỗ Thanh Hải
CTVVIP
3 tháng 10 2021
1 am doing - think - know
2 buys
3 rains - is raining
4 is cooking -* cooks
N
29 tháng 10 2021
Bạn tự vẽ sơ đồ mạch điện và tự làm tóm tắt nhé!
Bài 1:
b. \(U=IR=I\left(R1+R2\right)=0,4\left(15+2\right)=6,8\left(V\right)\)
c. \(I=I1=I2=\dfrac{U'}{R}=\dfrac{60}{15+2}=\dfrac{60}{17}\simeq3,5\left(A\right)\left(R1ntR2\right)\)
Bài 2:
\(5400kJ=1500\left(Wh\right)\)
a. \(A=Pt\Rightarrow P=\dfrac{A}{t}=\dfrac{1500}{1}=1500\left(W\right)\)
b. \(P=UI\Rightarrow I=\dfrac{P}{U}=\dfrac{1500}{220}=\dfrac{75}{11}\simeq6,82\left(A\right)\)
N
29 tháng 10 2021
Bài 3:
a. \(R=p\dfrac{l}{S}=1,1.10^{-6}\dfrac{3}{0,05.10^{-6}}=66\left(\Omega\right)\)
b. \(P=UI=U\left(\dfrac{U}{R}\right)=220.\left(\dfrac{220}{66}\right)=733,33\left(W\right)\)
c. \(A=Pt=733,33.\left(\dfrac{30}{60}\right)=366,665\left(Wh\right)=0,366665\left(kWh\right)=1319994\left(J\right)\)
Bài 4:
a. \(S=\pi\dfrac{d^2}{4}=\pi\dfrac{1^2}{4}=0,785\left(mm^2\right)\)
\(\Rightarrow R=p\dfrac{l}{S}=5,5.10^{-8}\dfrac{10}{0,785.10^{-6}}=\dfrac{110}{157}\simeq0,7\left(\Omega\right)\)
b. \(A=Pt=UIt=U\left(\dfrac{U}{R}\right)t=70\left(\dfrac{70}{0,7}\right).\dfrac{1}{3}=2333,33\left(Wh\right)=2,33333\left(kWh\right)\simeq8400000\left(J\right)\)
DT
Đỗ Thanh Hải
CTVVIP
4 tháng 10 2021
4 going to buy a lot of things for the party tomorrow
5 is go out somewhere for a drink
6 Jane going to travel around the world
7 short and fair
8 a good football player
9 a fast runner
10 hard workers
11 swim well
12 worked busily
1 A
2 D
3 C
4 A
5 A
DT
Đỗ Thanh Hải
CTVVIP
10 tháng 10 2021
1 C
2 A
3 D
4 A
5 B
6 D
7 C
8 C
II
1 A
2 B
III
1 deaf
2 countless
3 inventor
4 delivery
IV
1 He worked with deaf-mutes at Boston University in America
2 I am going to see the movie Dream city at 6.45 this evening
V
1 going to visit my friends next Sunday
2 go to the movie tonight
H
10 tháng 10 2021
hơi nhiều chút nhưng thôi cố làm vậi =((
8. careful enough to do that job.
9. going to come over to pick you up.
10. going to visit her grandparents tomorrow.
11. not going to buy some new books.
12. to play basketball this afternoon.
13. going to do tomorrow?
cấu trúc nè :3 intend to V = be going to V
14. to visit our teacher today.
15. to finish this homework now.
16. take care of her house.
17. to go home on time.
18. to ask my aunt and she's downstairs.
19. about coming to my house for lunch?
20. we meet inside the center, at the cafe corner?
b: \(=3-\sqrt{5}+4-\sqrt{5}=7-2\sqrt{5}\)