| @@ -1,116 +1,103 @@ |
| |
| |
| <!DOCTYPE html> |
| <!DOCTYPE html> |
| <html lang="en"> |
| <html lang="en"> |
| |
| |
| <head> |
| <head> |
| <meta charset="UTF-8" /> |
| <meta charset="utf-8"> |
| <meta name="viewport" content="width=device-width, initial-scale=1.0" /> |
| <meta name="viewport" content="width=device-width, initial-scale=1.0"> |
| <meta http-equiv="content-language" content="en"> |
| <meta http-equiv="content-language" content="en"> |
| <script async src="https://www.googletagmanager.com/gtag/js?id=G-DDMB38YMLD"></script> |
| <meta name="keywords" content="solutions, savchenko, physics problems, olympiad physics, physics book"> |
| |
| <meta name="description" content="A website with solutions to physics problems from Savchenko Textbook"> |
| <title>Savchenko Solutions</title> |
| <meta property="og:title" content="Savchenko Solutions"> |
| <meta property="og:image" content="img/logo.png"> |
| <meta property="og:image" content="img/logo.png"> |
| <meta property="og:title" content="Savchenko Solutions"/> |
| <meta property="og:description" content="A website with solutions to physics problems from Savchenko Textbook"> |
| <meta name="description" |
| <meta name="yandex-verification" content="6cfda41f74038368"> |
| content="A website with solutions to physics problems from Savenko Textbook" /> |
| <title>Savchenko Solutions</title> |
| <meta name="keywords" content="physics, olympiads, ipho, savchenko" /> |
| <link rel="stylesheet" href="https://savchenko-physics.github.io/css/css-latex/style.css"> |
| <link rel="stylesheet" href="https://savchenko-physics.github.io/css/css-latex/style.css" /> |
| <link rel="icon" href="https://savchenko-physics.github.io/img/logo.png" type="image/png"> |
| <link rel="icon" type="image/x-icon" href="https://savchenko-physics.github.io/img/favicon.ico"> |
| <script src="https://savchenko-physics.github.io/js/jquery-1.10.1.min.js"></script> |
| |
| <script async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.7/MathJax.js?config=TeX-MML-AM_CHTML"></script> |
| |
| <script type="text/x-mathjax-config"> |
| |
| MathJax.Hub.Config({ |
| |
| extensions: ['tex2jax.js'], |
| |
| jax: ['input/TeX', 'output/HTML-CSS'], |
| |
| tex2jax: { |
| |
| inlineMath: [['$', '$'], ['$', '$']], |
| |
| processEscapes: true, |
| |
| processClass: 'tex2jax', |
| |
| ignoreClass: 'html' |
| |
| }, |
| |
| showProcessingMessages: false, |
| |
| messageStyle: 'none' |
| |
| }); |
| |
| </script> |
| </head> |
| </head> |
| |
| <body style=""> |
| <body id="top"> |
| <header style="text-align:center;"> |
| <header> |
| |
| <h2>Solutions of Savchenko Physics Textbook</h2> |
| <h2>Solutions of Savchenko Physics Textbook</h2> |
| <p class="author"> |
| <p class="author"> |
| Aliaksandr Melnichenka <br/> |
| Aliaksandr Melnichenka <br/> |
| October 2023 |
| October 2023 |
| </p> |
| </p> |
| </header> |
| </header> |
| |
| |
| <main> |
| <h3 id="back-link"><a href="../">$\leftarrow$Back</a></h3> |
| <article> |
| |
| <h3 id="back-link"><a href="../">$\leftarrow$Back</a></h3> |
| <h3> Statement </h3> |
| |
| |
| <h4>Statement</h4> |
| <p> |
| <p> |
| $2.8.4$ |
| $2.8.4$ |
| Through three holes made in a desktop pass threads united by a common knot. At the free ending of each thread is hanged equal loads. Determine the angles between threads. There is no friction. |
| Through three holes made in a desktop pass threads united by a common knot. At the free ending of each thread is hanged equal loads. Determine the angles between threads. There is no friction. |
| </p> |
| </p> |
| |
| <center> |
| |
| <figure> |
| |
| <img src="statement.png" |
| |
| loading="lazy" alt="2.8.4" width="300" /> |
| |
| <figcaption> |
| |
| For problem 2.8.4 |
| |
| </figcaption> |
| |
| </figure> |
| |
| </center> |
| |
| <h4>Solution</h4> |
| |
| <p class="TxtSolutions"> |
| |
| Tension in each thread is the same ($T=mg$). Moreover, note that the absolute value of the sum of two any tensions must be equal to the third one which is also $T$ and be directed in opposed sense for maintain the equilibrium. So, consider for example the angle $\gamma$ |
| |
| </p> |
| |
| <center> |
| |
| <figure> |
| |
| <img src="draw.png" |
| |
| loading="lazy" alt="2.8.4" width="300" /> |
| |
| <figcaption> |
| |
| Top view |
| |
| </figcaption> |
| |
| </figure> |
| |
| </center> |
| |
| <center> |
| |
| $T_R = T = 2T\cos{\frac{\gamma}{2}}$ |
| |
| </center> |
| |
| <p class="TxtSolutions"> |
| |
| Hence |
| |
| </p> |
| |
| <center> |
| <center> |
| $\cos{\frac{\gamma}{2}} = 0.5$ |
| <figure> |
| |
| <img src="statement.png" |
| |
| loading="lazy" alt="1.5.3" width="200" /> |
| |
| <figcaption> |
| |
| For problem 1.5.3 |
| |
| </figcaption> |
| |
| </figure> |
| </center> |
| </center> |
| |
| |
| |
| <h3>Solution</h3> |
| |
| <p> |
| |
| Tension in each thread is the same ($T=mg$). Moreover, note that the absolute value of the sum of two any tensions must be equal to the third one which is also $T$ and be directed in opposed sense for maintain the equilibrium. So, consider for example the angle $\gamma$ |
| |
| </p> |
| |
| |
| <center> |
| <center> |
| $\gamma = \frac{2\pi}{3} = 120^\circ$ |
| <figure> |
| |
| <img src="draw.png" |
| |
| loading="lazy" alt="2.8.4" width="300" /> |
| |
| <figcaption> |
| |
| Top view |
| |
| </figcaption> |
| |
| </figure> |
| </center> |
| </center> |
| <p class="TxtSolutions"> |
| |
| |
| <p> |
| |
| $$T_R = T = 2T\cos{\frac{\gamma}{2}}$$ |
| |
| Hence |
| |
| $$\cos{\frac{\gamma}{2}} = 0.5$$ |
| |
| $$\gamma = \frac{2\pi}{3} = 120^\circ$$ |
| But, since the above condition of the sum of two any tensions always is true, the three angles must be equal. |
| But, since the above condition of the sum of two any tensions always is true, the three angles must be equal. |
| |
| $$\boxed{\alpha=\beta=\gamma=120^\circ}$$ |
| </p> |
| </p> |
| <center> |
| |
| $\boxed{\alpha=\beta=\gamma=120^\circ}$ |
| <p style="text-align: right; font-style: italic; font-size: 14;"> |
| </center> |
| |
| <p class="TxtSolutions" style="text-align: right; font-style: italic; font-size: 14;"> |
| |
| BSc. Luis Daniel Fernández Quintana<br> |
| BSc. Luis Daniel Fernández Quintana<br> |
| Physics Department (FCNE)<br> |
| Physics Department (FCNE)<br> |
| Universidad de Oriente, Cuba<br> |
| Universidad de Oriente, Cuba<br> |
| </p> |
| </p> |
| </article> |
| |
| </main> |
| |
| |
| |
| <script> |
| |
| MathJax = { |
| |
| tex: { |
| |
| inlineMath: [['$', '$'],], |
| |
| }, |
| |
| } |
| |
| const typeFaceToggle = document.getElementById('typeface-toggle') |
| |
| const typeface = document.getElementById('typeface') |
| |
| typeFaceToggle.addEventListener('click', () => { |
| |
| document.body.classList.toggle('libertinus') |
| |
| typeface.textContent = document.body.classList.contains('libertinus') ? 'Libertinus' : 'Latin Modern' |
| |
| }) |
| |
| |
| |
| const darkModeToggle = document.getElementById('dark-mode-toggle') |
| <footer class="row container"> |
| darkModeToggle.addEventListener('click', () => { |
| <br> |
| document.body.classList.toggle('latex-dark') |
| <p> |
| }) |
| <small> © <strong>Savchenko Solutions</strong>, 2023-2024 <br></small> |
| </script> |
| </p> |
| <script> |
| <p> |
| window.dataLayer = window.dataLayer || []; |
| <small>All rights belong to the authors. <br> Commercial use of materials - with the written permission of the authors. <br> astrosander01@gmail.com <br></small> |
| function gtag(){dataLayer.push(arguments);} |
| </p> |
| gtag('js', new Date()); |
| </footer> |
| |
| </body> |
| gtag('config', 'G-DDMB38YMLD'); |
| |
| </script> |
| |
| <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script> |
| |
| |
| |
| </body> |
| |
| |
| |
| </html> |
| </html> |