[原创]研究物体间的相互作用
<p class="MsoNormal" align="center" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center;"><b style="mso-bidi-font-weight: normal;"><span twffan="done" style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">研究物体间的相互作用</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" twffan="done" style="FONT-SIZE: 14pt;"><p></p></span></b></p><p></p><p></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt 24.75pt; TEXT-INDENT: -24.75pt; tab-stops: list 24.75pt; mso-list: l0 level1 lfo1;"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" twffan="done" style="mso-bidi-font-family: 宋体;"><span twffan="done" style="mso-list: Ignore;"><font face="">一、<span twffan="done" style="FONT: 7pt "";"> </span></font></span></span></b><b style="mso-bidi-font-weight: normal;"><span twffan="done" style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">单项选择题</span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">1</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">．下列力的说法中正确的是（</span><span lang="EN-US" twffan="done"><font face=""> C </font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">）</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">力是物体对物体的作用，所以只有直接接触的物体间才有力的作用。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">B.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">由有一定距离的磁铁间有相互作用力可知，力可以离开物体而独立存在。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">C.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">力是使物体发生形变和改变物体运动状态的原因。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">D.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">力的大小可以用天平测量。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">2</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">．关于重力的说法中正确的是（</span><span lang="EN-US" twffan="done"><font face=""> D<span twffan="done" style="mso-spacerun: yes;"> </span></font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">）</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">在落向地球时，物体受的重力大于它静止时受的重力。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">B.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">因重力的方向总是竖直向下的，故重力一定和地面垂直。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">C.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">重力就是物体对水平桌面的压力。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">D.</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">一个物体不论是静止还是运动，也不论是怎么运动，受到的重力都是一样。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">3</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">．下列关于重心的说法正确的是（</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>B </font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">）</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">、重心是物体的各部分所受重力的合力的作用点。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">B</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">、密度均匀形状规则的物体的重心必与其几何中心重合。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">C</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">、重心是物体上最重的一点。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">D</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">、直铁丝被弯曲后，重心便不在中点，但一定还在铁丝上。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">4</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">．下列说法中正确的是（</span><span lang="EN-US" twffan="done"><font face=""> B<span twffan="done" style="mso-spacerun: yes;"> </span></font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">）</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">有弹力必定有摩擦力，有摩擦力必定有弹力。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">B</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">轻杆不同于轻绳，弹力的方向可以不在杆的直线方向上。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">C</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">摩擦力的大小一定与物体所受的重力大小成比。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">D</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">摩擦力的方向总是与运动方向相反，起阻碍物体运动的作用</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">5</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">．关于下列说法中，正确的是（</span><span lang="EN-US" twffan="done"><font face=""> D </font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">）</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">一根绳子能承受的最大拉力是</span><span lang="EN-US" twffan="done"><font face="">G</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">，现把一重力为</span><span lang="EN-US" twffan="done"><font face="">G</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">的物体拴在绳的中点，两手靠拢分别握绳的两端，然后漫漫地向左右两边分开，当绳断时两段绳间夹角应稍大于</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A 30</font></span><span twffan="done" style="FONT-FAMILY: 宋体;">°</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>B 60</font></span><span twffan="done" style="FONT-FAMILY: 宋体;">°</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>C 90</font></span><span twffan="done" style="FONT-FAMILY: 宋体;">°</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>D 120</font></span><span twffan="done" style="FONT-FAMILY: 宋体;">°</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">6</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">．用手握住瓶子，使瓶子在竖直方向静止，如果握力加倍，则手对瓶子的摩擦力（</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>B </font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">）</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">A</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">握力越大，摩擦力越大。</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>B</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">只要瓶子不动，摩擦力大小与前面的因素无关。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><font face="">C</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">方向由向下变成向上。</span><span lang="EN-US" twffan="done"><font face=""><span twffan="done" style="mso-spacerun: yes;"> </span>D</font></span><span twffan="done" style="FONT-FAMILY: 宋体; mso-ascii-font-family: ''; mso-hansi-font-family: '';">手越干越粗糙，摩擦力越大。</span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" twffan="done"><p><font face=""></font></p></span><p></p><a href="http://www.21manager.com/dispbbs.asp?n=147,166961,0,0,0,0,0,0"></a></p>
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