试题与答案

某同学用单摆测重力加速度, ①他组装单摆时,在摆线上端的悬点处,用一块开有狭缝的

题型:实验题

题目:

某同学用单摆测重力加速度,

①他组装单摆时,在摆线上端的悬点处,用一块开有狭缝的橡皮夹牢摆线,再用铁架台的铁夹将橡皮夹紧,如图所示,这样做的目的是_______(填字母代号)

A.保证摆动过程中摆长不变

B.可使周期测量得更加准确

C.需要改变摆长时便于调节

D.保证摆球在同一竖直平面内摆动

②他组装好单摆后在摆球自然悬垂的情况下,用毫米刻度尺从悬点量到摆球的最低端的长度L=_________m,再用游标卡尺测量摆球直径D=________m,再测定了40次全振动的时间t=_________s,则单摆摆长l=_________m,重力加速度g=__________m/s2

 

③如果测得的g值偏小,可能的原因是_______(填写代号)。

A.测摆长时,忘记了摆球的半径

B.摆线上端悬点未固定,振动中出现松动,使摆线长度增加了

C.开始计时时,秒表过早按下

D.实验中误将39次全振动次数记为40次

④下列振动图象真实地描述了对摆长约为1 m的单摆进行周期测量的四种操作过程,图中横坐标原点表示计时开始,A、B、C均为30次全振动的图象,已知sin5°=0.087,sin15°=0.26,这四种操作过程合乎实验要求且误差最小的是________(填字母代号)。

答案:

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参考答案:A解析:本题考查的是《招标投标法实施条例》相关内容。招标人已收取投标保证金的,应当自收到投标人书面撤回通知之日起5日内退还。

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