Một chiếc ô tô đang chạy trên đoạn đường lát gạch, cứ cách khoảng 5 m lại có một rãnh nhỏ. Tần số dao động riêng của khung xe trên các lò xo giảm xóc là 0,5 Hz. Ô tô bị xóc mạnh nhất khi chạy với tốc độ bao nhiêu?
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Câu hỏi liên quan
Mark the letter A, B, C or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.
a. However, it also presents challenges, such as the need for digital literacy and the importance of maintaining privacy.
b. It has made information more accessible than ever, enabling us to learn and share knowledge across the globe in an instant.
c. As we navigate this rapidly evolving landscape, finding a balance between embracing innovation and fostering genuine human connections becomes essential.
d. Technology has transformed the way we live, work, and connect with one another.
e. From smartphones that keep us connected to advanced medical devices that save lives, technology enhances our daily experiences.
Thành tựu nào sau đây thuộc về tin sinh học?
Nếu biết \(\text{sin}\alpha =\frac{5}{13},\,\left( \frac{\pi }{2}<\alpha <\pi \right),\,\text{cos}\beta =\frac{3}{5},\,\left( 0<\beta <\frac{\pi }{2} \right)\) thì giá trị đúng của \(\text{cos}\left( \alpha -\beta \right)\) là
Cho tập hợp A=[−3;2). Phần bù của tập A trong R là
Quan hệ cung - cầu có vai trò như thế nào đối với nhà nước?
Phát biểu nào sau đây không đúng về dân cư, dân tộc ở nước ta?
Choose the word or phrase (A, B, C, or D) that best fits each space in the following passage.
To many people, their friends are the most important in their life. Really good friends always (16)____joys and sorrows with you and never turn their backs on you. Your best friend may be someone you have known all your life or someone you have grown (17) ___with.
There are all sorts of things that can (18)____about this special relationship. It may be the result of enjoying the same activities and sharing experiences. Most of us have met someone that we have immediately felt relaxed with as if we had known them for ages. However, it really takes you years to get to know someone well (19)___to consider your best friend.
To the majority of us, this is someone we trust completely and (20)___understands us better than anyone else. It's the person you can tell him or her your most intimate secrets.
(19)____
Choose A, B, C or D to answer the question.
Which of the following situations best exemplifies “collaboration,” where individuals work together to achieve a common goal?
Read the following passage about studying abroad and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
Successful students often do the followings while studying. First, they have an overview before reading. Next, they look for important information and pay greater attention to it (which often needs jumping forward or backward to process information). They also relate important points to one another. Also, they activate and use their prior knowledge. When they realize that their understanding is not good, they do not wait to change strategies. Last, they can monitor understanding and take action to correct or “fix up” mistakes in comprehension.
Conversely, students with low academic achievement often demonstrate ineffective study skills. [I] They tend to assume a passive role in learning and rely on others (e.g., teachers, parents) to monitor their studying. [II] For example, low-achieving students often do not monitor their understanding of content; they may not be aware of the purpose of studying; and they show little evidence of looking back or employing “fix-up” strategies to fix understanding problems. [III] Students who struggle with learning new information seem to be unaware that they must extend effort beyond simply reading the content to understand and remember it. [IV]
Children with learning disabilities do not plan and judge the quality of their studying. Their studying may be disorganized. Students with learning problems face challenges with personal organization as well. They often have difficulty keeping track of materials and assignments, following directions, and completing work on time. Unlike good studiers who employ a variety of study skills in a flexible yet purposeful manner, low-achieving students use a restricted range of study skills. They cannot explain why good study strategies are important for learning; and they tend to use the same, often ineffective study approach for all learning tasks, ignoring task content, structure or difficulty.
Which word below is opposite in meaning to “ineffective”?
Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each the numbered blanks from 31 to 35.
“One month on since the devastating earthquake hit Türkiye and Syria, the scale of the humanitarian response has yet to meet the enormous needs of displaced Syrian families and children (31)_____have suffered from compounded crises for almost 12 years now,” said Johan Mooij, director of World Vision’s Syria crisis response. “It is crucial that (32)_____ access channels to northwest Syria remain open, and that aid deliveries are scaled up through earmarked funding for the emergency response. Only this will ensure that children’s mental health needs are covered, and their trauma addressed.”
Snow and bitter winter weather have placed children at great risk of hypothermia (33)_____ they struggle to survive in sub-zero temperatures. Many survivors have had to sleep in cars, outside, or in makeshift shelters. Doctors (34)_____ that children are also at risk of exposure to waterborne diseases such as cholera or Hepatitis A due to the damage to shelters and water infrastructure.
These children are now even more vulnerable to family separation, exploitation, and abuse. As buildings are deemed unsafe, they also are unable to return to school.
“In northern Syria, in particular, the threats to children from abuse were already extreme. The soaring poverty, within a warzone, now devastated by earthquakes, has created an unimaginable number of challenges, and suffering for children,” says Johan, director of the Syria crisis response in Amman, Jordan. “This earthquake has created the perfect environment for a health crisis -fueled by reduced healthcare capacity and disease (35)_____.”
Read the passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 20 to 29.
We are living through a boom in greenwashing - the strategic use of comforting environmental claims to disguise business-as-usual pollution. Picture a chief executive whose company emits millions of tonnes of CO2 Genuine decarbonisation would require bruising boardroom discussions, huge capital outlays, and a complete redesign of the firm's model. Far easier is to hire a creative agency to plaster products with labels such as "carbon-neutral" or "net-zero," calming critics, investors, and even eco-conscious children while emissions continue unsolved.
This tactic meets consumers at every tum. Airline websites promise guilt-free flights, petrol pumps boast zero- - Impact fuel, and even supermarket bacon is marketed as net-zero. [1] Advertising trickery is ancient, yet today's greenwashing - the practice of deliberately covering ongoing pollution in eco-friendly language - has flourished only recently. The expression surfaced in the 1980s amid oil spills and growing climate science, but the real explosion has come as public anxiety over global heating and biodiversity loss has intensified. Faced with mounting scrutiny, many boards prefer glossy PR to structural reform. Such corporate sleight of hand has become so pervasive that regulators in Europe and the United States are scrambling to tighten rules on environmental claims, yet enforcement still lags behind marketing creativity. [II] The fossil-fuel sector exemplifies the issue. After decades covertly sowing doubt about climate science, oil and gas giants have grasped that direct denial is reputationally toxic. They have therefore swapped their denial tactics for a "green" paint-sprayer, trumpeting token investments in renewables while expanding drilling.
Why does this matter? Greenwashing and climate denial share a core objective: to postpone the emission cuts urgently required to avert climate breakdown. [III] Whereas denial invites opposition, greenwashing lulls the public into believing problems are already solved. Under this collective illusion, pressure on high-emitting firms evaporates and the radical decisions needed to transform energy, transport, and food systems are delayed indefinitely. [IV] Greenwashing thus acts as a soothing lullaby, leading society toward ecological ruin with a tune of comforting half- truths. Exposing this deception is essential If clichés are to be replaced by real, measurable emission cuts.
(Adapted from https:/www.greenpeace.org.uk)
Which of the following is NOT stated as an example of greenwashed products or services?
- Thành phố nào sau đây ở nước ta trực thuộc tỉnh?
Hai nguồn kết hợp A, B cùng pha, cùng biên độ, cách nhau 40 cm. Khoảng cách giữa hai điểm dao động với biên độ cực đại gần nhau nhất trên đoạn AB là 0,8 cm. Điểm M thuộc miền giao thoa cách nguồn A một đoạn 25cm và cách nguồn B một đoạn 22cm. Dịch chuyển nguồn B từ từ dọc theo phương AB ra xa nguồn B đoạn 10 cm thì số lần điểm M chuyển thành điểm dao động với biên độ cực đại là:
Phát biểu nào đúng khi nói về hệ dẫn truyền tim?
Con lắc lò xo có độ cứng \(25.{\pi ^2}\) N/m một đầu cố định, đầu còn lại gắn vật có khối lượng m = 250 gam dao động điều hòa theo phương nằm ngang. Người ta tác dụng lên con lắc một ngoại lực tuần hoàn \(F = 4.\cos \left( {2\pi ft} \right)\left( N \right)\). Thay đổi tần số ngoại lực từ 6,15 Hz đến 8,75 Hz thì biên độ dao động đạt giá trị lớn nhất khi tần số là bao nhiêu ? (tần số tính theo đơn vị Hz)
Đáp án:
Cho hàm số y=f(x) xác định trên R và có bảng biến thiên như hình vẽ sau:
Hàm số đã cho đồng biến trên khoảng nào sau đây?
Trong những năm 1975 – 1985, Việt Nam có hoạt động đối ngoại nào sau đây?
Read the following passage about the Pathways from Today's Actions to Tomorrow's World and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
As we stand at the crossroads of environmental decision-making, the actions we take today will shape our world in 2050. Scientists warn that we're skating on thin ice with current consumption patterns and carbon emissions. Global temperatures could rise by 2-4 degrees Celsius unless significant changes occur within the next decade. Many countries have pledged to achieve carbon neutrality by 2050, but these promises require immediate implementation. Individual choices in transportation, energy usage, and consumption can collectively influence whether future generations inherit a sustainable planet or face severe climate consequences.
[I] Technological innovation represents our greatest hope for addressing environmental challenges by 2050. [II] Renewable energy sources like solar and wind are becoming increasingly affordable, potentially replacing fossil fuels entirely within thirty years. [III] Electric vehicles may dominate transportation networks, while vertical farming could transform food production in urban areas. [IV] However, these technological solutions must be developed and deployed equitably to avoid creating new disparities between wealthy and developing nations.
Social structures will undergo dramatic transformation by 2050 as demographic shifts reshape communities worldwide. Aging populations in developed countries will necessitate new approaches to healthcare, retirement, and social support systems. Meanwhile, climate migration may force millions to relocate from vulnerable coastal and drought-prone regions. Education systems must evolve to prepare our students for jobs that don't yet exist, emphasizing their adaptability and lifelong learning. Cities will need to become more resilient, incorporating green spaces and sustainable infrastructure to support growing populations.
Economic models must fundamentally change by 2050 to balance prosperity with environmental responsibility. The traditional focus on continuous growth may shift toward measuring success through wellbeing indicators rather than GDP alone. Circular economy principles will likely replace linear production models, with products designed for reuse and recycling. Resource-sharing platforms may become more prevalent, reducing individual consumption while maintaining living standards. Companies implementing genuinely sustainable practices will thrive, while those clinging to environmentally harmful methods may disappear entirely. The transition presents both challenges and opportunities for businesses willing to embrace innovation and sustainability.
The word “their” in paragraph 3 refers to _________.
Cho tam giác ABC có \(a = 4,b = 5,c = 7\). Bán kính đường tròn ngoại tiếp R của tam giác ABC bằng?
Tài nguyên khoáng sản đa dạng ở khu vực Mỹ Latinh là cơ sở để phát triển ngành nào sau đây?