【单选题】用压电式单向脉动力传感器测量一正弦变化的力,压电元件用两片压电陶瓷并联,压电常数为 200 ́ 10 -12 C/N ,电荷放大器的反馈电容 C f =2000pF ,测得输出电压 u o =5sin w t ( V )。求: 1 )该压电传感器产生的总电荷 Q (峰值)为 ________pC 。 2 )此时作用在其上的正弦脉动力(瞬时值)为 _______N 。
【单选题】70-Year-Old Lives the College Experience 70 岁老人体验大学生活 Vocabulary and Expressions 词语预习 graduation ceremony bachelor fraternity screw-up 1. What kind of degree does Mr. Reid obtain?