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| + | <header style="text-align:center;"> | ||
| + | <h2>Solutions of Savchenko Physics Textbook</h2> | ||
| + | <p class="author"> | ||
| + | Aliaksandr Melnichenka <br/> | ||
| + | October 2023 | ||
| + | </p> | ||
| + | </header> | ||
| + | |||
| + | <h3 id="back-link"><a href="../">$\leftarrow$Back</a></h3> | ||
| + | |||
| + | <h3> Statement </h3> | ||
| + | <p> | ||
| + | $1.1.5^*.$ Three microphones located on the same straight line at points $A$, $B$, $C$ recorded successively at the moments $t_A > t_B > t_C$ the sound of an explosion that occurred at point $O$, which lies on the segment $AC$. Find the length of the segment $AO$ if $AB = BC = L$. At what point in time did the explosion occur? | ||
| + | <center> | ||
| + | <figure> | ||
| + | <img src="statement.png" | ||
| + | loading="lazy" width="230" /> | ||
| + | <figcaption> | ||
| + | For problem 1.1.5 | ||
| + | </figcaption> | ||
| + | </figure> | ||
| + | </center> | ||
| + | </p> | ||
| + | <h3>Solution</h3> | ||
| + | <p> | ||
| + | |||
| + | <p class="TxtSolutions"> | ||
| + | Let the explosion occurred at time $t_0$, then the time of signal registration at point $A$ is equal to:<br> | ||
| + | </p> | ||
| + | $$t_A = t_0 + \frac{L + x}{c}, \, (1)$$ | ||
| + | <p class="TxtSolutions"> | ||
| + | where $x = BO$.<br><br> | ||
| + | Similar to point $B$<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$t_B = t_0 + \frac{x}{c}, \,(2)$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | For point $C$<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$t_C = t_0 + \frac{L - x}{c}, \,(3)$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | Let's subtract the second equation from the first equation:<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$t_A – t_B = \frac{L}{c}. \,(4)$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | And from the first equation we subtract the third equation<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$t_A – t_C = \frac{2x}{c}. \,(5)$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | From equation $(4)$ let's express $c = \frac{L}{t_A – t_B}$, а из $(5)$ $x = \frac{t_A – t_C}{2} \cdot c$. Then the required distance<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$AO = L + x = L + \frac{t_A – t_C}{2}\frac{L}{t_A – t_B}$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | After the transformation<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$AO = \frac{3t_A – 2t_B – t_C}{2(t_A – t_B)} \cdot L. \, (6)$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | To determine the moment of time at which the explosion occurred, we substitute in the expression<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$t_A = t_0 + \frac{L + x}{c}, \; c = \frac{L}{t_A – t_B}$$ | ||
| + | $$\frac{t_A – t_C}{2} = \frac{x}{c}$$ | ||
| + | </p> | ||
| + | <p class="TxtSolutions"> | ||
| + | after transformations<br> | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$t_0 = t_B - \frac{1}{2} \cdot (t_A – t_C)$$ | ||
| + | </p> | ||
| + | </p> | ||
| + | |||
| + | <h4>Answer</h4> | ||
| + | <p> | ||
| + | $$AO = \frac{3t_A – 2t_B – t_C}{2(t_A – t_B)} \cdot L, \; t_0 = t_B - \frac{1}{2} \cdot (t_A – t_C)$$ | ||
| + | </p> | ||
| + | |||
| + | |||
| + | |||
| + | <footer class="row container"> | ||
| + | <br> | ||
| + | <p> | ||
| + | <small> © <strong>Savchenko Solutions</strong>, 2023-2024 <br></small> | ||
| + | </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> | ||
| + | </p> | ||
| + | </footer> | ||
| + | </body> | ||
| + | |||
| + | </html> | ||
| @@ -0,0 +1,135 @@ | |||
| <!DOCTYPE html> | |||
| <html lang="en"> | |||
| <head> | |||
| <meta charset="utf-8"> | |||
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| <meta property="og:title" content="Savchenko Solutions"> | |||
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| <meta property="og:description" content="A website with solutions to physics problems from Savchenko Textbook"> | |||
| <meta name="yandex-verification" content="6cfda41f74038368"> | |||
| <title>Savchenko Solutions</title> | |||
| <link rel="stylesheet" href="https://savchenko-physics.github.io/css/css-latex/style.css"> | |||
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| extensions: ['tex2jax.js'], | |||
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| tex2jax: { | |||
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| }, | |||
| showProcessingMessages: false, | |||
| messageStyle: 'none' | |||
| }); | |||
| </script> | |||
| </head> | |||
| <body style=""> | |||
| <header style="text-align:center;"> | |||
| <h2>Solutions of Savchenko Physics Textbook</h2> | |||
| <p class="author"> | |||
| Aliaksandr Melnichenka <br/> | |||
| October 2023 | |||
| </p> | |||
| </header> | |||
| <h3 id="back-link"><a href="../">$\leftarrow$Back</a></h3> | |||
| <h3> Statement </h3> | |||
| <p> | |||
| $1.1.5^*.$ Three microphones located on the same straight line at points $A$, $B$, $C$ recorded successively at the moments $t_A > t_B > t_C$ the sound of an explosion that occurred at point $O$, which lies on the segment $AC$. Find the length of the segment $AO$ if $AB = BC = L$. At what point in time did the explosion occur? | |||
| <center> | |||
| <figure> | |||
| <img src="statement.png" | |||
| loading="lazy" width="230" /> | |||
| <figcaption> | |||
| For problem 1.1.5 | |||
| </figcaption> | |||
| </figure> | |||
| </center> | |||
| </p> | |||
| <h3>Solution</h3> | |||
| <p> | |||
| <p class="TxtSolutions"> | |||
| Let the explosion occurred at time $t_0$, then the time of signal registration at point $A$ is equal to:<br> | |||
| </p> | |||
| $$t_A = t_0 + \frac{L + x}{c}, \, (1)$$ | |||
| <p class="TxtSolutions"> | |||
| where $x = BO$.<br><br> | |||
| Similar to point $B$<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$t_B = t_0 + \frac{x}{c}, \,(2)$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| For point $C$<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$t_C = t_0 + \frac{L - x}{c}, \,(3)$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| Let's subtract the second equation from the first equation:<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$t_A – t_B = \frac{L}{c}. \,(4)$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| And from the first equation we subtract the third equation<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$t_A – t_C = \frac{2x}{c}. \,(5)$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| From equation $(4)$ let's express $c = \frac{L}{t_A – t_B}$, а из $(5)$ $x = \frac{t_A – t_C}{2} \cdot c$. Then the required distance<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$AO = L + x = L + \frac{t_A – t_C}{2}\frac{L}{t_A – t_B}$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| After the transformation<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$AO = \frac{3t_A – 2t_B – t_C}{2(t_A – t_B)} \cdot L. \, (6)$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| To determine the moment of time at which the explosion occurred, we substitute in the expression<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$t_A = t_0 + \frac{L + x}{c}, \; c = \frac{L}{t_A – t_B}$$ | |||
| $$\frac{t_A – t_C}{2} = \frac{x}{c}$$ | |||
| </p> | |||
| <p class="TxtSolutions"> | |||
| after transformations<br> | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$t_0 = t_B - \frac{1}{2} \cdot (t_A – t_C)$$ | |||
| </p> | |||
| </p> | |||
| <h4>Answer</h4> | |||
| <p> | |||
| $$AO = \frac{3t_A – 2t_B – t_C}{2(t_A – t_B)} \cdot L, \; t_0 = t_B - \frac{1}{2} \cdot (t_A – t_C)$$ | |||
| </p> | |||
| <footer class="row container"> | |||
| <br> | |||
| <p> | |||
| <small> © <strong>Savchenko Solutions</strong>, 2023-2024 <br></small> | |||
| </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> | |||
| </p> | |||
| </footer> | |||
| </body> | |||
| </html> | |||