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en/2.1.56.md
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| + | ### Statement | ||
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| + | $2.1.56.$ [Insert the problem statement] | ||
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| + | ### Solution | ||
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| + | ### Statement | ||
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| + | $2.1.56.$ A body of mass $M$ is connected by a thread of length $l$ to an axis around which it revolves with an angular velocity $\\omega$. Find the tension force of the thread. The dimensions of the body are small; neglect gravity. Replace the thread with a uniform rope of mass $m$ and find its tension force at a distance $x$ from the axis of rotation. | ||
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| + | ### Solution | ||
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| + |  | ||
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| + | 1\\. In the case of a weightless and inextensible thread, its tension is determined as: | ||
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| + | $$ | ||
| + | T = F_i = \\frac{Mv^2}{L} = \\frac{M\\omega^2l^2}{l} | ||
| + | $$ | ||
| + | |||
| + | $$ | ||
| + | \\boxed{T = M\\omega^2l} | ||
| + | $$ | ||
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| + | 2\\. Let us isolate a specified cross-section of the rope at distance $x$ and determine the mass of its outer part of length $(l-x)$: | ||
| + | |||
| + | $$ | ||
| + | m_x = m\\frac{l-x}{l} | ||
| + | $$ | ||
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| + | 3\\. Let us determine the distance from the rotation axis $Oz$ to the center of mass of this rope segment: | ||
| + | |||
| + | $$ | ||
| + | r_x = l - \\frac{l-x}{2} | ||
| + | $$ | ||
| + | |||
| + | $$ | ||
| + | r_x = \\frac{l+x}{2} | ||
| + | $$ | ||
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| + | 4\\. The tension of the rope at section $x$ will be caused by the inertial (centrifugal) force of the rotating mass $M$ and the mass of the outer rope segment $m_x$: | ||
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| + | $$ | ||
| + | \\boxed{T_x = M\\omega^2l + \\frac{m\\omega^2(l^2-x^2)}{2l}} | ||
| + | $$ | ||
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| + | #### Answer | ||
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| + | $$ | ||
| + | T = M\\omega^2l | ||
| + | $$ | ||
| + | |||
| + | $$ | ||
| + | T_x = M\\omega^2l + m\\omega^2(l^2 - x^2)/(2l) | ||
| + | $$ | ||
| + | |||
| + | #### Answer | ||
| + | |||
| + | [Insert a concise answer or boxed result] | ||
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| ### Statement | |||
| $2.1.56.$ [Insert the problem statement] | |||
| ### Solution | |||
| ### Statement | |||
| $2.1.56.$ A body of mass $M$ is connected by a thread of length $l$ to an axis around which it revolves with an angular velocity $\\omega$. Find the tension force of the thread. The dimensions of the body are small; neglect gravity. Replace the thread with a uniform rope of mass $m$ and find its tension force at a distance $x$ from the axis of rotation. | |||
| ### Solution | |||
|  | |||
| 1\\. In the case of a weightless and inextensible thread, its tension is determined as: | |||
| $$ | |||
| T = F_i = \\frac{Mv^2}{L} = \\frac{M\\omega^2l^2}{l} | |||
| $$ | |||
| $$ | |||
| \\boxed{T = M\\omega^2l} | |||
| $$ | |||
| 2\\. Let us isolate a specified cross-section of the rope at distance $x$ and determine the mass of its outer part of length $(l-x)$: | |||
| $$ | |||
| m_x = m\\frac{l-x}{l} | |||
| $$ | |||
| 3\\. Let us determine the distance from the rotation axis $Oz$ to the center of mass of this rope segment: | |||
| $$ | |||
| r_x = l - \\frac{l-x}{2} | |||
| $$ | |||
| $$ | |||
| r_x = \\frac{l+x}{2} | |||
| $$ | |||
| 4\\. The tension of the rope at section $x$ will be caused by the inertial (centrifugal) force of the rotating mass $M$ and the mass of the outer rope segment $m_x$: | |||
| $$ | |||
| \\boxed{T_x = M\\omega^2l + \\frac{m\\omega^2(l^2-x^2)}{2l}} | |||
| $$ | |||
| #### Answer | |||
| $$ | |||
| T = M\\omega^2l | |||
| $$ | |||
| $$ | |||
| T_x = M\\omega^2l + m\\omega^2(l^2 - x^2)/(2l) | |||
| $$ | |||
| #### Answer | |||
| [Insert a concise answer or boxed result] | |||