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+ <meta name="description" content="A body located on a horizontal plane is pulled by the thread in the horizontal direction. Draw a graph of the dependence of the friction force acting on the body from the plane on the tension force of the thread. Initially, the body is motionless. Body weight 10 kg, coefficient of friction 0.51.">
+ <meta name="author" content="Aliaksandr Melnichenka">
+ <meta name="date" content="2023-10" scheme="YYYY-MM">
+ <meta property="og:title" content="A body located on a horizontal plane is pulled by the thread in the horizontal direction. Draw a graph of the dependence of the friction force acting on the body from the plane on the tension force of the thread. Initially, the body is motionless. Body weight 10 kg, coefficient of friction 0.51.">
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+ <title>A body located on a horizontal plane is pulled by the thread in the horizontal direction. Draw a graph of the dependence of the friction force acting on the body from the plane on the tension force of the thread. Initially, the body is motionless. Body weight 10 kg, coefficient of friction 0.51.</title>
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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="../../#2.1">$\leftarrow$Back</a></h3>
+
+ <h3> Statement </h3>
+ <p>
+ $2.1.19.$ A body located on a horizontal plane is pulled by the thread in the horizontal direction. Draw a graph of the dependence of the friction force acting on the body from the plane on the tension force of the thread. Initially, the body is motionless. Body weight $10$ kg, coefficient of friction $0.51$.
+</p>
+<center>
+ <figure>
+ <img src="https://savchenkosolutions.com/2/2.1.19/statement.png"
+ loading="lazy" width="140" />
+ <figcaption>
+ For problem $2.1.19$
+ </figcaption>
+ </figure>
+</center>
+<p>
+ </p>
+
+ <h3>Solution</h3>
+ <p>
+ <p>
+Let's do a visual experiment, put a pen on a piece of paper and slowly move it to the side
+</p>
+<br>
+<center>
+<figure>
+<img src="https://savchenkosolutions.com/2/2.1.19/demo.gif"
+loading="lazy" width="350" />
+<figcaption>
+Demonstration of a pen falling
+</figcaption>
+</figure>
+</center>
+<p>
+At some point, the pen will go in the opposite direction and slip out from under your hand
+</p>
+<br>
+<center>
+<figure>
+<img src="https://savchenkosolutions.com/2/2.1.19/draw.png"
+loading="lazy" width="250" />
+<figcaption>
+The pen is in a critical condition
+</figcaption>
+</figure>
+</center>
+<p>
+Using a special program, we will determine the angle of the pen at this moment
+</p>
+<br>
+<center>
+<figure>
+<img src="https://savchenkosolutions.com/2/2.1.19/angle.jpg"
+loading="lazy" width="450" ​​/>
+<figcaption>
+Measuring the critical angle
+</figcaption>
+</figure>
+</center>
+<p>
+It worked
+$$ \boxed{\alpha = 7^{\circ}} $$
+Let's display the forces acting on the handle
+</p>
+<br>
+<center>
+<figure>
+<img src="https://savchenkosolutions.com/2/2.1.19/draw1.png"
+loading="lazy" width="180" />
+<figcaption>
+Forces acting on the handle
+</figcaption>
+</figure>
+</center>
+<p>
+Since the friction force is the force of static friction
+$$ F_{тр} = \mu N $$
+Let us write down the equilibrium condition at the critical moment
+$$ \left\{\begin{matrix}
+ \mu N = F \sin \alpha\\
+ N = F \cos \alpha
+ \end{matrix}\right. $$
+Where
+$$ \boxed{\mu = \tan \alpha} $$
+We substitute experimental data
+$$ \mu = \tan 7^{\circ} = 0.12 $$
+</p>
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