Một vật có khối lượng m dao động điều hòa với biên độ A. Khi chu kì tăng 3 lần thì năng lượng của vật sẽ
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
Năng lượng của vật là
\(\begin{array}{l}
W = \frac{1}{2}m{\omega ^2}{A^2}\\
= \frac{1}{2}m{\left( {\frac{{2\pi }}{T}} \right)^2}{A^2}
\end{array}\)
Do đó, khi chu kì tăng 3 lần thì năng lượng giảm \({3^2} = 9\) lần.
Đáp án: B
Tài liệu "Bộ Đề Kiểm Tra Giữa Học Kì I - Năm Học 2023-2024 - Vật Lí 11" tổng hợp các đề kiểm tra từ nhiều trường THPT trên toàn quốc, được biên soạn bám sát chương trình học. Đề thi bao gồm các dạng bài trắc nghiệm và tự luận, tập trung vào các chủ đề: động học chất điểm, các định luật Newton, công và công suất, và các dạng năng lượng cơ bản. Tài liệu giúp học sinh củng cố kiến thức, rèn luyện kỹ năng giải bài tập và chuẩn bị tốt cho kỳ kiểm tra giữa học kỳ I.
Câu hỏi liên quan
Tôn giáo bị cấm đoán ngặt nghèo thời Nguyễn là:
Con hãy lựa chọn đáp án Đúng hoặc Sai
Nội dung của hai khổ thơ đầu bài thơ Mùa xuân chín là “khung cảnh tươi mới, đầy sức sống của mùa xuân” đúng hay sai?
Bộ phận nào sau đây thuộc phần chủ động của li hợp ma sát?
Lỗi lặp từ là sự lặp lại
Read the following 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 31 to 40.
Working on Your Workout
(I) Although appreciating a balanced diet and regular exercise, most people do not know how to exercise properly. Consequently, they usually rush through their workouts, or they make the same common workout mistakes. (II) Exercising the right way is important for people who are worried about their health and their appearance. (III) However, if someone is not working out properly, they will not see the results they want. Therefore, training experts have devised tips to teach people how to exercise correctly in order to achieve the greatest health benefits. (VI)
One of the most common workout mistakes is doing the same routine over and over again. This does not challenge your muscles, and it can actually prevent muscles from growing and repairing themselves. Instead of always sticking to the same old workout, it is important to change your routine every six to eight weeks. It is also important to add a variety of workouts to your routine, such as swimming, yoga, or biking, to make sure your whole body stays fit. This will help make your workouts more interesting, and benefit your health and muscle development as well.
Another mistake people tend to make is to work out too hard, too often. Your body needs to rest between workouts; otherwise, no progress will be made. It is best to keep the number of hard workout routines to no more than two per week. Then, for those who don’t want to get off schedule by skipping a day, shorter workouts of about twenty minutes can be used on other days. For more variety in workouts, you could also plan an easier routine for forty to sixty minutes between days of shorter, more intense workouts. Experts recommend, however, taking at least one day off completely each week, especially after several hard workout days in a row.
In reality, no one is perfect. However, if you want to make a difference in your overall health, there are some things you can do. Stretch before and after every workout. Do not rush your routine, and do not work out too little or too much. Remember not to make these common workout mistakes, and always have fun while exercising!
Which of the following can be inferred from the passage?
Hoàn thành bảng sau:
Số hiệu nguyên tử (Z) Số electron lớp ngoài cùng Kim loại, phi kim hay khí hiếm? 9 16 18 20 30 Những phát biểu nào sau đây đúng khi nói về vai trò của lớp vật liệu hấp thụ dao động trong đầu dò của máy siêu âm?
Đâu là ý nghĩa tích cực của tự do hóa thương mại mở rộng?
Xác định một từ/cụm từ SAI về ngữ pháp/hoặc ngữ nghĩa/logic/phong cách.
Cần hạn chế bắn pháo hoa hoặc sử dụng loại pháo hoa ít tiếng ồn để giảm ô nhiễm không khí, giảm căng thẳng cho vật nuôi và động vật hoang dã.
Read the following passage about education in Nepal 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.
Fashion in the 1960s reflected the cultural and political upheaval of the time. The hippie and counterculture movement gave rise to accessories like Pocahontas-style headbands and medallions worn around the neck. Hippies wore long, loosely fitting clothing, often in natural fabrics. Hemlines rose as Mary Quant popularized the miniskirt and hot pants in her lines for JC Penney. And mod fashion, with brightly colored space-age geometric patterns, shift dresses and colored tights became the mainstream. Both miniskirts and mod-shift dresses were worn with knee-high go-go boots.
[A] During the 1970s, the loose-fitting hippie clothes of the prior decade gave way to exotic fabrics and bell-bottom jeans for men and women. Hemlines continued to rise and hot pants continued their popularity, reflecting the flashy style of the decade. However, the 1970s also saw the popularity of a longer hemline, from mid-calf to ankle-length. [B] Women wore peasant-style clothing, especially blouses with off-the-shoulder necklines and lace trim, with their jeans or skirts. [C] Disco fashion emerged, featuring bright patterns and tightly fitting clothing meant to show off the body. Platform shoes elevated their wearer, male or female, anywhere from two to four inches or more. [D]
The 1980s saw another fashion upheaval. Angst-ridden punks wore Dr. Marten and steel-toed army boots, chains, tartan patterns, and bondage pants. Punks focused more on their hair during this period, dying, teasing and chopping their hair into asymmetric styles that seemed to defy gravity. Women—and men—experimented with heavy eyeliner in a variety of colors. Women wore neon colors, jelly shoes, tight jeans, leggings, leg warmers and oversized sweatshirts. Menswear-inspired looks also became popular for both sexes. Men wore ‘power suits,’ named so for their price, which made these suits a reflection of the wealth of the wearer. Women’s jackets featured big shoulder pads that made the shoulders appear higher and larger, similar to the male silhouette.
1990’s fashion was far more subdued than the garish, wild styles of the 1980s. Bands like Nirvana influenced the grunge look, which featured rock-concert tee shirts under plaid flannel shirts, jeans and long, greasy hair. Overalls were worn by both sexes, either with one or both shoulder straps unhooked. The punk style of the 1870s and 1980s evolved into the goth fashion trend, which featured black clothing, black boots and studded bracelets in the style of bands like Nine Inch Nails and Marilyn Manson.
The phrase “gave rise to” in paragraph 1 mostly means ______.
Hệ số nhiệt điện trở α của kim loại phụ thuộc vào yếu tố nào sau đây?
Tổ chức nào sau đây đóng vai trò quan trọng trong việc bảo tồn giá trị của các di sản trên thế giới?
Read the following passage about the Second Acts That Inspire 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.
Life often presents us with unexpected challenges that force us back to the drawing board. Whether due to personal setbacks, career changes, or unforeseen circumstances, the courage to begin again can lead to remarkable transformations. Many inspiring individuals have shown that it's never too late to reinvent oneself and pursue new dreams. Throughout history, countless people have overcome seemingly impossible situations through sheer determination.
[I] Take J.K. Rowling, for instance. Before becoming a literary sensation, she was a struggling single mother living on welfare. [II] Her determination eventually paid off when her books became a global phenomenon, proving that setbacks can become stepping stones to success. [III] This remarkable turnaround demonstrates how resilience and unwavering belief in oneself can overcome seemingly insurmountable obstacles. Despite facing depression and financial hardship, she never gave up on her dreams. [IV]
Colonel Harland Sanders' story is another testament to the power of starting anew. At the age of 65, when most people contemplate retirement, he found himself struggling financially after his restaurant failed. Instead of giving up, he traveled across America, sleeping in his car while pitching his chicken recipe to restaurant owners. His recipe for success wasn't just about the perfect blend of herbs and spices; it was about persistence and determination. After facing over 1,000 rejections, he finally established Kentucky Fried Chicken, which grew into a global empire. His unwavering spirit and dedication inspired generations of entrepreneurs worldwide.
These inspiring stories remind us that failure is not final, but rather a chance to redirect our path. Every setback carries the seed of an equal or greater opportunity, and sometimes the end of one chapter is simply the beginning of a better one. The key lies in having the courage to take that first step, even when the future seems uncertain. As these remarkable individuals have shown, it's never too late to rewrite your story and create a powerful second act. Their journeys teach us that persistence and courage ultimately lead to success.
Which of the following best paraphrases the underlined sentence in paragraph 4?
Cho hàm số . Khi đó có giá trị bằng?
Read the following passage about human life expectancy 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 23 to 30.
Milu was born in a small village in the north of India, and never had the chance of going to school, because her family needed her to work. So she grew up never having learned to read or write. She was a little sad about it, but she didn't let it upset her too much, and tried to think about other things.
She went through life, never being able to do what she wanted, because she felt that if she couldn't read, then she was somehow less than everybody else. This meant that she didn't make many friends and didn't go out much. She thought people would think she was stupid, and she didn't want them to laugh at her.
When she was fifty-six, she got a job cleaning a school and when she had finished her work, she used to sit and watch the little kids do their lessons. She didn't realise that one of the teachers watched her while she watched the kids, and one day, as she was about to leave, the teacher asked her to sit in the class. The kids thought it was very funny, but the teacher patiently started Milu on her first lesson to learn to read.
That was a few years ago, and now Milu can read and write as well as any of the other kids. She still cleans the school because she likes her job, but she doesn't feel less than everybody else anymore. The teacher, who is now her friend, sometimes gives her a book to read and she learns about people living in other parts of the world.
She has a granddaughter who studies at the same school, and sometimes she helps her with her homework. Being able to do that makes her feel so happy that when she stays alone she has a little cry. When she was in her little village as a child, she would never have dreamt that one day she would be able to help her granddaughter with her homework. She owes gratitude to her teacher friend for the gift she was given.
Which of the following is NOT what Milu gains from learning?
Theo quy định pháp luật, tình huống nào sau đây được ứng cử đại biểu Quốc hội và đại biểu Hội đồng nhân dân các cấp?
Hình ảnh thơ nào không xuất hiện trong hai câu thực của bài thơ Cảm xúc bài thơ - Đỗ Phủ?
Cho biểu thức \(T=3x-2y-4\) với \(x\) và \(y\) thỏa mãn hệ bất phương trình: \(\left\{ \begin{align} x-y-1\le 0 \\ x+4y+9\ge 0 \\ x-2y+3\ge 0 \\ \end{align} \right.\). Biết \(T\) đạt giá trị nhỏ nhất khi \(x={{x}_{0}}\) và \(y={{y}_{0}}\). Tính \(x_{0}^{2}+y_{0}^{2}\).
Loại thuế được cộng vào giá bán hàng hóa, dịch vụ và do người tiêu dùng trả khi sử dụng sản phẩm đó được gọi là gì?
Cho đoạn lệnh sau:
x=20
if x%2==0:
x=x+10
else:
x=x-10;
Sau khi thực hiện đoạn chương trình x nhận giá trị bao nhiêu?