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| + | <meta name="description" content="The particle, after leaving the source, flies at a constant speed for a distance L, and then decelerates with acceleration a. At what speed will the particle have the shortest travel time from its departure to its stop?"> | ||
| + | <meta name="author" content="Aliaksandr Melnichenka"> | ||
| + | <meta name="date" content="2023-10" scheme="YYYY-MM"> | ||
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| + | <header style="text-align:center;"> | ||
| + | <h2>Solutions of Savchenko Problems in Physics</h2> | ||
| + | <p class="author"> | ||
| + | Aliaksandr Melnichenka <br/> | ||
| + | October 2023 | ||
| + | </p> | ||
| + | </header> | ||
| + | |||
| + | <h3 id="back-link"><a href="../#1.2">$\leftarrow$Back</a></h3> | ||
| + | |||
| + | <h3> Statement </h3> | ||
| + | <p> | ||
| + | $1.2.8^*.$ The particle, after leaving the source, flies at a constant speed for a distance $L$, and then decelerates with acceleration $a$. At what speed will the particle have the shortest travel time from its departure to its stop? | ||
| + | </p> | ||
| + | |||
| + | <h3>Solution</h3> | ||
| + | <p> | ||
| + | <p> | ||
| + | On a constant velocity interval, the velocity is: | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $$v_0 = \frac{L}{t}$$ | ||
| + | </p> | ||
| + | <p> | ||
| + | During the deceleration interval the velocity changes as | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $v(t) = v_0-at \Rightarrow v_0=at$ | ||
| + | </p> | ||
| + | <p> | ||
| + | Equating the equations, we obtain | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $L=at^2$ | ||
| + | </p> | ||
| + | <p> | ||
| + | From where | ||
| + | </p> | ||
| + | <p style="text-align: center;"> | ||
| + | $v_0 = \sqrt{La}$ | ||
| + | </p> | ||
| + | </p> | ||
| + | |||
| + | <h4>Answer</h4> | ||
| + | <p> | ||
| + | $$v = \sqrt{La}$$ | ||
| + | </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> | ||
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| @@ -0,0 +1,97 @@ | |||
| <!DOCTYPE html> | |||
| <html lang="en"> | |||
| <head> | |||
| <meta charset="utf-8"> | |||
| <meta name="viewport" content="width=device-width, initial-scale=1.0"> | |||
| <meta http-equiv="content-language" content="en"> | |||
| <meta name="keywords" content="Savchenko Problems in Physics, Savchenko solutions, physics problems, physics olympiad preparation, IPhO, Jaan Kalda"> | |||
| <meta name="description" content="The particle, after leaving the source, flies at a constant speed for a distance L, and then decelerates with acceleration a. At what speed will the particle have the shortest travel time from its departure to its stop?"> | |||
| <meta name="author" content="Aliaksandr Melnichenka"> | |||
| <meta name="date" content="2023-10" scheme="YYYY-MM"> | |||
| <meta property="og:title" content="The particle, after leaving the source, flies at a constant speed for a distance L, and then decelerates with acceleration a. At what speed will the particle have the shortest travel time from its departure to its stop?"> | |||
| <meta property="og:image" content="img/logo.png"> | |||
| <meta property="og:description" content="The particle, after leaving the source, flies at a constant speed for a distance L, and then decelerates with acceleration a. At what speed will the particle have the shortest travel time from its departure to its stop?"> | |||
| <meta name="yandex-verification" content="6cfda41f74038368"> | |||
| <title>The particle, after leaving the source, flies at a constant speed for a distance L, and then decelerates with acceleration a. At what speed will the particle have the shortest travel time from its departure to its stop?</title> | |||
| <link rel="stylesheet" href="https://savchenkosolutions.com/css/css-latex/style.css"> | |||
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| messageStyle: 'none' | |||
| }); | |||
| </script> | |||
| </head> | |||
| <body style=""> | |||
| <header style="text-align:center;"> | |||
| <h2>Solutions of Savchenko Problems in Physics</h2> | |||
| <p class="author"> | |||
| Aliaksandr Melnichenka <br/> | |||
| October 2023 | |||
| </p> | |||
| </header> | |||
| <h3 id="back-link"><a href="../#1.2">$\leftarrow$Back</a></h3> | |||
| <h3> Statement </h3> | |||
| <p> | |||
| $1.2.8^*.$ The particle, after leaving the source, flies at a constant speed for a distance $L$, and then decelerates with acceleration $a$. At what speed will the particle have the shortest travel time from its departure to its stop? | |||
| </p> | |||
| <h3>Solution</h3> | |||
| <p> | |||
| <p> | |||
| On a constant velocity interval, the velocity is: | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $$v_0 = \frac{L}{t}$$ | |||
| </p> | |||
| <p> | |||
| During the deceleration interval the velocity changes as | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $v(t) = v_0-at \Rightarrow v_0=at$ | |||
| </p> | |||
| <p> | |||
| Equating the equations, we obtain | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $L=at^2$ | |||
| </p> | |||
| <p> | |||
| From where | |||
| </p> | |||
| <p style="text-align: center;"> | |||
| $v_0 = \sqrt{La}$ | |||
| </p> | |||
| </p> | |||
| <h4>Answer</h4> | |||
| <p> | |||
| $$v = \sqrt{La}$$ | |||
| </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> | |||
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