Một vật dao động điều hòa có phương trình: x=Acos(ωt+φ) cm. Gọi v và a lần lượt là vận tốc và gia tốc của vật. Hệ thức đúng là
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
- $v = -A\omega\sin(\omega t + \varphi)$
- $a = -A\omega^2\cos(\omega t + \varphi)$
Suy ra:
- $\dfrac{v^2}{\omega^2} = A^2\sin^2(\omega t + \varphi)$
- $\dfrac{a^2}{\omega^4} = A^2\cos^2(\omega t + \varphi)$
Do đó: $A^2 = \dfrac{v^2}{\omega^2} + \dfrac{a^2}{\omega^4}$
Câu hỏi liên quan
Read the following passage about generation gap 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.
[I] The generation gap refers to the differences in attitudes, values, and beliefs between older and younger generations. [II] With rapid advancements in technology and shifting societal norms, the generation gap has become more apparent. [III] As younger generations grow up with modern technology and global connectivity, they frequently experience a world vastly different from that of their parents and grandparents. [IV]
One of the key reasons behind the generation gap is the rapid pace of technological change. Older generations, who grew up in a world without the internet, smartphones, or social media, often find it difficult to relate to the digital lifestyles of younger people. On the other hand, younger generations have been exposed to technology from a young age, shaping their values and communication styles. Additionally, differences in social values, such as views on work, family, and personal freedom, also contribute to the gap. These differing experiences create misunderstandings and a lack of common ground between generations.
The consequences of the generation gap can be significant, especially in family dynamics and workplaces. In families, the divide can lead to conflicts between parents and children, as each generation struggles to understand the other’s worldview. In the workplace, generational differences may affect teamwork, communication, and productivity. Younger employees may prioritize flexibility and innovation, while older generations may value stability and traditional work ethics. These differences can lead to friction, decreased collaboration, and a sense of alienation among coworkers.
To bridge the generation gap, open communication and mutual understanding are essential. Both older and younger generations need to be open to learning from each other and appreciating different perspectives. For instance, older generations can offer wisdom and experience, while younger generations can share their knowledge of technology and new trends. Encouraging intergenerational dialogue through family discussions, mentoring programs, or team-building activities in the workplace can help foster respect and collaboration. By recognizing and embracing their differences, both generations can work together to create a more harmonious society.
The word ‘their’ in paragraph 2 refers to ______.
Cho hình chóp S.ABCD có đáy ABCD là hình chữ nhật và SA⊥(ABCD).
Hình chiếu vuông góc của SC lên mặt phẳng ABCD là
Phần II. Câu trắc nghiệm đúng sai. Thí sinh trả lời từ câu 1 đến câu 4. Trong mỗi ý a), b), c), d) ở mỗi câu, thí sinh chọn đúng hoặc sai.
Cho các phát biểu về hệ tuần hoàn máu của người bình thường:
Một vệ tinh nhân tạo chuyển động tròn đều quanh Trái Đất ở độ cao bằng bán kính Trái Đất. Lấy gia tốc rơi tự do tại mặt đất g=10m/s2 và bán kính Trái Đất bằng R=6400km. Chu kì quay quanh Trái Đất của vệ tinh là:
Trong thí nghiệm tìm hiểu tính tự động của tim ếch, nếu thắt thêm một sợi chỉ vào vị trí 1/3 tính từ mỏm tim, thấy mỏm tim không đập dù để sau một khoảng thời gian dài, hiện tượng này chứng tỏ điều gì?
Cuối thế kỉ XIX, quốc gia Đông Nam Á không bị chủ nghĩa thực dân xâm lược là:
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12.
How the Generation Gap Plays Out in the Workplace
As a recruiter, I am in constant communication with executive clients and HR colleagues. I regularly (7) ________ on candidates I’ve placed, to see how they are getting on in their new roles. Here are some of the important generational differences I see that can lead to potential (8) ________ if not properly understood:
Communication styles
• The young generation is more (9) ________, quick to offer constructive criticism, individualistic, with a more casual approach.
• Gen X values hard work and long hours, a/k/a ‘The Grind’ – they are more skeptical, formal, and uncompromising.
Leadership styles
• The young generation is extremely open-mindeD. They resist micromanagement, and resent pressure. (10) ________ factor that sets them apart is their emphasis on work-life balance.
• (11) ________, their Generation X supervisors, on the other hand, are intensely focussed on the organisational processes that brought the company success; they tend to prioritise (12) ________ and the bottom line.
Có thể thực hiện bao nhiêu kiểu phép lai khác nhau về kiểu gen nếu chỉ xét một gen có 2 alen (A, a) tồn tại trên cả NST giới tính X và Y?
- Số nucleon trung hòa trong hạt nhân \(_{13}^{27}{\rm{Al}}\) là
Enthalpy tạo thành chuẩn của một đơn chất bền là
Read the following passage about the A Vision of a Harmonious Multicultural Society 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.
By 2050, our world will have undergone remarkable transformations in how different cultures coexist. The walls that once divided nations are vanishing into thin air as global citizens embrace diversity like never before. Technology will serve as the great equalizer, with translation devices making language barriers a thing of the past. In urban centers worldwide, neighborhoods will showcase architectural influences from multiple cultures, creating spaces where everyone feels at home regardless of their background. Public spaces will feature gardens with plants from different continents, symbolic of how various cultures can thrive together in one environment.
[I] Education systems will prioritize cultural literacy alongside traditional subjects. [II] Schools will teach world history from multiple perspectives rather than through a single cultural lens. [III] Students will routinely participate in virtual exchange programs, allowing them to form friendships with peers around the world without leaving their classrooms. [IV] Government policies will recognize that a harmonious multicultural society requires institutional support, with resources allocated to community centers where cultural exchange happens organically through shared meals, festivals, and collaborative art projects.
Economic systems will evolve to value diverse approaches to business and innovation. Companies will actively seek employees from varied backgrounds, recognizing that diverse teams create more innovative solutions. Traditional knowledge from indigenous communities will be respected and incorporated into sustainable development practices. The entertainment industry will produce content that authentically represents multiple cultures, moving beyond stereotypes to show the complexity within each tradition. Digital platforms will help preserve endangered languages and cultural practices through accessible archives and learning tools.
The greatest achievement of this harmonious world will be a new understanding of human identity. People will identify with multiple cultural traditions simultaneously without feeling conflicted about their loyalties. Holidays from various traditions will be celebrated collectively, creating new hybrid celebrations that honor multiple heritages. The concept of "us versus them" will gradually fade as people recognize shared values across different traditions. While challenges will remain, the dominant attitude will be one of curiosity rather than fear when encountering differences.
Which of the following is NOT mentioned as a feature of the world in 2050?
Trong không gian Oxyz, cho hai điểm A(−2;3;2) và B(2;1;0). Mặt phẳng trung trực của đoạn thẳng AB có phương trình là
Một con lắc đơn có độ dài \({l_1}\) dao động với chu kì \({T_1} = 4s\). Một con lắc đơn khác có độ dài \({l_2}\) dao động tại nơi đó với chu kì \({T_2} = 3s\). Chu kì dao động của con lắc đơn có độ dài \({l_1} - {l_2}\) xấp xỉ bằng
Read the following passage about the cultural diversity and mark the letter A, B, C, or D to indicate the best answer to each of the following questions from 31 to 40.
[I] In today’s globalized world, cultural diversity has become a fundamental aspect of many societies. [II] Many countries are experiencing increasing levels of migration. [III] With the rise of immigration and the blending of traditions, people from various cultural backgrounds are now living side by side in cities across the globe. [IV]
One of the key advantages of cultural diversity is the richness it adds to a society. Different cultures introduce unique perspectives, foods, languages, and traditions, which help people broaden their understanding of the world. In schools and workplaces, cultural diversity fosters creativity and innovation, as individuals from different backgrounds approach problems in novel ways. However, there are also challenges associated with living in culturally diverse communities. Misunderstandings and communication barriers can arise when people are unfamiliar with each other’s customs and values. To address these issues, societies must encourage cultural sensitivity and create opportunities for cross-cultural exchange.
Governments and institutions around the world are beginning to implement policies that promote inclusion and respect for cultural differences. By celebrating diversity through events, education, and media representation, communities can create environments where people feel valued regardless of their background. Ultimately, embracing cultural diversity helps to build more peaceful and harmonious societies.
The word ‘novel’ in paragraph 2 could best be replaced by ______.
Theo thuyết tiến hoá hiện đại, phát biểu nào sau đây không đúng?
- Trong các trường hợp sau, trường hợp nào nội năng của vật giảm?
Thế nào là mô phân sinh?
Sự phân hóa của thiên nhiên nước ta theo chiều bắc - nam là do
Sự phân bố các điểm dân cư nông thôn thường được biểu hiện bằng phương pháp
Một nguồn phát sóng cơ dao động theo phương trình . Biết dao động tại hai điểm gần nhau nhất trên cùng một phương truyền sóng cách nhau 0,5 m có độ lệch pha là . Tốc độ truyền sóng đó là