問題詳情
16.一蹦极运动员身系弹性蹦极绳从水面上方的高台下落，到最低点时距水面还有数米距离。假定空气阻力可忽略，运动员可视为质点，下列说法正确的是
(A). 运动员到达最低点前重力势能始终减小
(B). 蹦极绳张紧后的下落过程中，弹性力做负功，弹性势能增加
(C). 蹦极过程中，运动员、地球和蹦极绳所组成的系统机械能守恒
(D). 蹦极过程中，重力势能的改变与重力势能零点的选取有关
(A). 运动员到达最低点前重力势能始终减小
(B). 蹦极绳张紧后的下落过程中，弹性力做负功，弹性势能增加
(C). 蹦极过程中，运动员、地球和蹦极绳所组成的系统机械能守恒
(D). 蹦极过程中，重力势能的改变与重力势能零点的选取有关
參考答案
答案：A,B,C
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)
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