本题目来源于试卷: Overweight and underweight，类别为 美国物理杯赛(Physics Bowl)
[单选题]
07.13: Astudent weighing 50q.s:nn,bpw2 v0 N stands on a bathroo1ac a imcxl5n4dsosh+b+: odi etrv1b0(/ a8. m scale in the school’s elevator. When + l4xbdo.i me101s5+vh at/saaoid8r (c:cn b the scale reads 520 N, the elevator must be
A. accelerating upward.
B. accelerating downward.
C. moving upward at a constant speed.
D. moving downward at a constant speed.
E. at rest.
参考答案: A
本题详细解析:
暂无
| 
