单选题
kind
patient
thankful
friendly
单选题
educational
sorry
embarrassed
realistic
单选题
much
little
no
any
单选题
depended on
looked forward to
stayed away from
came back to
单选题
teaching
training
telling
treating
单选题
and
or
so
but
单选题 如图所示,光滑轻绳AB穿过系有重物的小环,当绳两端固定在同一水平高度时,小环恰在绳的中点O,并达到平衡现保持A端不动,将B端在同一水平高度缓慢向右平移,则在B端平衡的过程中,绳OA、OB段所受拉力FOA和FOB的变化是( ).
FOA增大,FOB减小
FOA减小,FOB增大
FOA和FOB同时增大
FOA和FOB同时减小
单选题 电梯里放置一个弹簧秤,秤上挂着一个质量为1kg的物体.电梯以2m/s2的加速度上升,弹簧秤的读数是( ).
9.8N
7.8N
11.8N
0