当RLC串联串联电路发生谐振时,下列说法正确的是()。
A.电感上的电压达到最大
B.电容上的电压达到最大
C.电阻上的电压达到最大
D.电路的频率达到最大
参考答案:C
甲物体从阳台自由下落,已知物体在下落过程中最后2秒的位移是60m。(g=10m/s2)
(1)阳台离地面的高度
(2)最后1s的平均速度为多少
(3)若甲释放2s后,乙也从阳台释放,要甲、乙同时落地,需给乙多大的向下的初速度.
The man didn't know ________ the thief broke into the house and stole all his valuable things. [ ]
A. it was when that
B. when it was that
C. that it was when
D. was it when that