题目3单选题
.下列系统各有多少个自由度: (1)在一平面上滑动的粒子; (2)可以在一平面上滑动并可围绕垂直于平面的轴转动的硬币; (3)一弯成三角形的金属棒在空间自由运动A. 2, 3, 5B. 3, 6, 6C. 3, 4 , 6D. 2, 3 , 6
题目4单选题
<img src="https://tihai-oss-cloud.itihey.com/img/e88f7e36110afa12c120bdcd47fdff8b.png">A. <img src="https://tihai-oss-cloud.itihey.com/img/8c5ef7843787b94d6c3d0d481124cd61.png">, <img src="https://tihai-oss-cloud.itihey.com/img/8c5ef7843787b94d6c3d0d481124cd61.png">, <img src="https://tihai-oss-cloud.itihey.com/img/d730790862c46fc10aef09f22848e16c.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/8c5ef7843787b94d6c3d0d481124cd61.png">, <img src="https://tihai-oss-cloud.itihey.com/img/3da44c72b375dcc7f694b0df59296040.png"> , <img src="https://tihai-oss-cloud.itihey.com/img/d730790862c46fc10aef09f22848e16c.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/8c5ef7843787b94d6c3d0d481124cd61.png">, <img src="https://tihai-oss-cloud.itihey.com/img/d730790862c46fc10aef09f22848e16c.png">, <img src="https://tihai-oss-cloud.itihey.com/img/3da44c72b375dcc7f694b0df59296040.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/3da44c72b375dcc7f694b0df59296040.png">, <img src="https://tihai-oss-cloud.itihey.com/img/8c5ef7843787b94d6c3d0d481124cd61.png">, <img src="https://tihai-oss-cloud.itihey.com/img/d730790862c46fc10aef09f22848e16c.png">