题目
在“探究弹力和弹簧伸长量的关系,并测定弹簧的劲度系数”的实验中,实验装置如图所示.所挂钩码的重力相当于对弹簧提供了向右的恒定拉力.实验时先测出不挂钩码时弹簧的自然长度,再将5个钩码逐个挂在绳子的下端,每次测出相应的弹簧总长度. (1)有一个同学通过以上实验测量后把6组数据描点在坐标系图中,请作出F-L图线. (2)由此图线可得出该弹簧的原长L0=________ cm,在弹性限度内的劲度系数k=________ N/m. (3)试根据该同学以上的实验情况,帮助他设计一个记录实验数据的表格(不必填写其实验测得的具体数据). (4)该同学实验时,把弹簧水平放置与弹簧悬挂放置相比较, 优点在于:________________________________________________________________ 缺点在于:________________________________________________________________
答案: (1) F-L图线如图所示:(最后一个点连线也可以)········································· (2分) (2) L0=5 cm········································································································· (2分) k=20 N/m···································································································· (2分) (3) 记录数据的表格如上表················································································· (2分) (4) 优点是:可以避免弹簧自身重力对实验的影响.······································· (1分) 缺点是:弹簧与桌面及绳子与滑轮间存在的摩擦会造成实验误差············ (1分)