Bài tập Chủ đề 5
Hướng dẫn giải Bài 6 (Trang 105 SGK Vật lý 10, Bộ Cánh diều)
<p>Một quả b&oacute;ng golf c&oacute; khối lượng 0,046 kg. Tốc độ của quả b&oacute;ng ngay sau khi rời khỏi gậy golf l&agrave; 50 m/s.</p> <p>Gậy đ&aacute;nh g&ocirc;n tiếp x&uacute;c với b&oacute;ng trong thời gian 1,3 mili gi&acirc;y. T&iacute;nh lực trung b&igrave;nh do gậy đ&aacute;nh g&ocirc;n t&aacute;c dụng</p> <p>l&ecirc;n quả b&oacute;ng.</p> <p><strong>Lời giải:</strong></p> <p>&Aacute;p dụng c&ocirc;ng thức t&iacute;nh lực trung b&igrave;nh:&nbsp;<span id="MathJax-Element-1-Frame" class="mjx-chtml MathJax_CHTML" style="box-sizing: border-box; display: inline-block; line-height: 0; text-indent: 0px; text-align: left; text-transform: none; font-style: normal; font-weight: normal; font-size: 21.78px; letter-spacing: normal; overflow-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; position: relative;" tabindex="0" role="presentation" data-mathml="&lt;math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot;&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mi&gt;&amp;#x394;&lt;/mi&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;&amp;#x394;&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/math&gt;"><span id="MJXc-Node-1" class="mjx-math" aria-hidden="true"><span id="MJXc-Node-2" class="mjx-mrow"><span id="MJXc-Node-3" class="mjx-mi"></span></span></span><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>F</mi><mo>=</mo><mfrac><mrow><mi>&Delta;</mi><mi>p</mi></mrow><mrow><mi>&Delta;</mi><mi>t</mi></mrow></mfrac></math><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mrow><mi></mi></mrow></mfrac></math></span></p> <p>Theo đề b&agrave;i ta c&oacute;:</p> <p>+ Vận tốc l&uacute;c đầu của quả b&oacute;ng golf v<sub>0</sub>&nbsp;= 0</p> <p>+ Vận tốc l&uacute;c sau của quả b&oacute;ng golf&nbsp; v<sub>1</sub>&nbsp;= 50 m/s.</p> <p>Thay số:&nbsp;</p> <p><span id="MathJax-Element-2-Frame" class="mjx-chtml MathJax_CHTML" style="box-sizing: border-box; display: inline-block; line-height: 0; text-indent: 0px; text-align: left; text-transform: none; font-style: normal; font-weight: normal; font-size: 21.78px; letter-spacing: normal; overflow-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; position: relative;" tabindex="0" role="presentation" data-mathml="&lt;math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot;&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;&amp;#x2212;&lt;/mo&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;&amp;#x394;&lt;/mi&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;046.50&lt;/mn&gt;&lt;mo&gt;&amp;#x2212;&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;3.10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;&amp;#x2212;&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1769&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;23&lt;/mn&gt;&lt;mtext&gt;&amp;#x2009;&lt;/mtext&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/math&gt;"><span id="MJXc-Node-12" class="mjx-math" aria-hidden="true"><span id="MJXc-Node-13" class="mjx-mrow"><span id="MJXc-Node-14" class="mjx-mi"></span></span></span><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>F</mi><mo>=</mo><mfrac><mrow><mi>m</mi><msub><mi>v</mi><mn>1</mn></msub><mo>&minus;</mo><mi>m</mi><msub><mi>v</mi><mn>0</mn></msub></mrow><mrow><mi>&Delta;</mi><mi>t</mi></mrow></mfrac><mo>=</mo><mfrac><mrow><mn>0</mn><mo>,</mo><mn>046</mn><mo>.</mo><mn>50</mn><mo>&minus;</mo><mn>0</mn></mrow><mrow><mn>1</mn><mo>,</mo><mn>3</mn><mo>.</mo><msup><mn>10</mn><mrow><mo>&minus;</mo><mn>3</mn></mrow></msup></mrow></mfrac><mo>=</mo><mn>1769</mn><mo>,</mo><mn>23</mn><mi>N</mi></math><math xmlns="http://www.w3.org/1998/Math/MathML"><mi></mi></math></span></p> <p>Vậy lực trung b&igrave;nh do gậy đ&aacute;nh g&ocirc;n t&aacute;c dụng l&ecirc;n quả b&oacute;ng c&oacute; độ lớn l&agrave; 1769,23 N</p>
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