| <!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"> |
| <meta name="keywords" content="solutions, savchenko, physics problems, olympiad physics, physics book"> | | <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"> | | <meta name="description" content="A website with solutions to physics problems from Savchenko Textbook"> |
| <meta property="og:title" content="Savchenko Solutions"> | | <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:description" content="A website with solutions to physics problems from Savchenko Textbook"> | | <meta property="og:description" content="A website with solutions to physics problems from Savchenko Textbook"> |
| <meta name="yandex-verification" content="6cfda41f74038368"> | | <meta name="yandex-verification" content="6cfda41f74038368"> |
| <title>Savchenko Solutions</title> | | <title>Savchenko Solutions</title> |
| <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" href="https://savchenko-physics.github.io/img/logo.png" type="image/png"> |
| <script src="https://savchenko-physics.github.io/js/jquery-1.10.1.min.js"></script> | | <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 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"> | | <script type="text/x-mathjax-config"> |
| MathJax.Hub.Config({ | | MathJax.Hub.Config({ |
| extensions: ['tex2jax.js'], | | extensions: ['tex2jax.js'], |
| jax: ['input/TeX', 'output/HTML-CSS'], | | jax: ['input/TeX', 'output/HTML-CSS'], |
| tex2jax: { | | tex2jax: { |
| inlineMath: [['$', '$'], ['$', '$']], | | inlineMath: [['$', '$'], ['$', '$']], |
| processEscapes: true, | | processEscapes: true, |
| processClass: 'tex2jax', | | processClass: 'tex2jax', |
| ignoreClass: 'html' | | ignoreClass: 'html' |
| }, | | }, |
| showProcessingMessages: false, | | showProcessingMessages: false, |
| messageStyle: 'none' | | messageStyle: 'none' |
| }); | | }); |
| </script> | | </script> |
| </head> | | </head> |
| <body style=""> | | <body style=""> |
| <header style="text-align:center;"> | | <header style="text-align:center;"> |
| <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> |
| $2.8.1$ | | $2.8.1$ |
| The figure shows structures that hold a load weighing 10 kg. The cables are represented by thin lines, the rod is represented by a double line. Determine the tension force of the cables for case a and the force acting on the rod from the side of the cable thrown over it for case b. | | The figure shows structures that hold a load weighing 10 kg. The cables are represented by thin lines, the rod is represented by a double line. Determine the tension force of the cables for case a and the force acting on the rod from the side of the cable thrown over it for case b. |
| </p> | | </p> |
| <center> | | <center> |
| <figure> | | <figure> |
| <img src="statement.png" | | <img src="statement.png" |
| loading="lazy" alt="2.8.1" width="400" /> | | loading="lazy" alt="2.8.1" width="400" /> |
| <figcaption> | | <figcaption> |
| For problem 2.8.1 | | For problem 2.8.1 |
| </figcaption> | | </figcaption> |
| </figure> | | </figure> |
| </center> | | </center> |
| <h3>Solution</h3> | | <h3>Solution</h3> |
| <p> | | <p> |
| Let's consider the following figure | | Let's consider the following figure |
| </p> | | </p> |
| <center> | | <center> |
| <figure> | | <figure> |
| <img src="draw.png" | | <img src="draw.png" |
| loading="lazy" alt="2.8.1" width="500" /> | | loading="lazy" alt="2.8.1" width="500" /> |
| <figcaption> | | <figcaption> |
| Force analysis | | Force analysis |
| </figcaption> | | </figcaption> |
| </figure> | | </figure> |
| </center> | | </center> |
| <p> | | <p> |
| $a$. Applying Newton Second Law for $x$-direction | | $a$. Applying Newton Second Law for $x$-direction |
| $$T_2~\cos{30^\circ}-T_1~\cos{30^\circ}=0$$ | | $$T_2~\cos{30^\circ}-T_1~\cos{30^\circ}=0$$ |
| $$T_1=T_2 \;(1)$$ | | $$T_1=T_2 \;(1)$$ |
| for $y$-direction | | for $y$-direction |
| $$(T_1+T_2)~\sin{30^\circ} = mg \;(2)$$ | | $$(T_1+T_2)~\sin{30^\circ} = mg \;(2)$$ |
| Let be $T_1=T_2=T$, so, back to $(2)$ | | Let be $T_1=T_2=T$, so, back to $(2)$ |
| $$2T~\sin{30^\circ}=mg$$ | | $$2T~\sin{30^\circ}=mg$$ |
| $$T = \frac{mg}{2~\sin{30^\circ}} = mg = \boxed{98~\rm{N}}$$ | | $$T = \frac{mg}{2~\sin{30^\circ}} = mg = \boxed{98~\rm{N}}$$ |
| $b$. According figure, | | $b$. According figure, |
| $$F^2 = T^2+T^2 = 2T^2$$ | | $$F^2 = T^2+T^2 = 2T^2$$ |
| We consider the same tension $T$ because we suppose the threads are unextensible. | | We consider the same tension $T$ because we suppose the threads are unextensible. |
| $$F = \sqrt{2}~T \;(3)$$ | | $$F = \sqrt{2}~T \;(3)$$ |
| Applying Newton Second Law | | Applying Newton Second Law |
| $$T = mg \;(4)$$ | | $$T = mg \;(4)$$ |
| Putting $(4)$ into $(3)$ | | Putting $(4)$ into $(3)$ |
| $$F = \sqrt{2}~mg = \boxed{138~\rm{N}}$$ | | $$F = \sqrt{2}~mg = \boxed{138~\rm{N}}$$ |
| Note: Calculations were made considering $g$ = 9.8 N/kg and $\sqrt{2}$ = 1.41. | | Note: Calculations were made considering $g$ = 9.8 N/kg and $\sqrt{2}$ = 1.41. |
| </p> | | </p> |
| <p style="text-align: right; font-style: italic; font-size: 14;"> | | <p 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> |
| | | |
| | | |
| | | |
| <footer class="row container"> | | <footer class="row container"> |
| <br> | | <br> |
| <p> | | <p> |
| <small> © <strong>Savchenko Solutions</strong>, 2023-2024 <br></small> | | <small> © <strong>Savchenko Solutions</strong>, 2023-2024 <br></small> |
| </p> | | </p> |
| <p> | | <p> |
| <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> | | <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> |
| </p> | | </p> |
| </footer> | | </footer> |
| </body> | | </body> |
| | | |
| </html> | | </html> |
