【多选题】如图(甲)所示,两根足够长的平行光滑金属导轨固定在水平面内,导轨间距为1.0m,左端连接阻值R=4.0Ω的电阻,匀强磁场磁感应强度B=0.5T、方向垂直导轨所在平面向下。质量m=0.2kg、长度l=1.0m、电阻r=1.0Ω的金属杆置于导轨上,向右运动并与导轨始终保持垂直且接触良好,t=0时对杆施加一平行于导轨方向的外力F,杆运动的v-t图像如图(乙)所示,其余电阻不计、则
C.
从t=0开始,金属杆运动距离为5m时电阻R两端的电压为1.6V
D.
在0~3.0s内,外力F大小随时间t变化的关系式是F=0.1+0.1t(N)
【多选题】有关复式记账法的表述中,正确的有( )
A.
复式记账法一般应在两个或两个以上账户中登记,但有时也在一个账户中登记
D.
我国所有企事业单位都必须统一采用复式记账法中的借贷记账法进行会计核算
【单选题】Which of the following is NOT true, according to the passage?
A.
The book is comprehensive because it includes various arts.
B.
The book is controversial because it contains arts that offend.
C.
The book cannot be readily accessible through multimedia.
D.
The book may be objectionable to some children or parents.
【简答题】一质量m=3.0kg,长L=1.0m的匀质棒放在桌面上,可绕通过其中心的竖直固定轴转动,t=0 s时棒的角速度【图片】,由于受到恒定的阻力矩作用,t=10 s时,棒停止运动,则棒所受到的阻力矩大小为 【图片】.(结果用小数表示)
【简答题】如图所示,长为L=0.2 m、电阻为r=0.3 Ω、质量为m=0.1 kg的金属棒CD垂直放在位于水平面上的两条平行光滑金属导轨上,两导轨间距也为L,棒与导轨接触良好,导轨电阻不计,导轨左端接有R=0.5 Ω的电阻,量程为0~3.0 A的电流表串联在一条导轨上,量程为0~1.0 V的电压表接在电阻R的两端,垂直导轨平面的匀强磁场向下穿过平面.现以向右恒定的外力F使金属棒右移,当金属棒以v=2 m/...
【单选题】According to this introduction, the best way to use this book is______.
A.
to become a good mathematical modeler
B.
to tackle as many mathematical problems as possible
C.
to do the problems given in the book on one's own
D.
to have confidence in constructing mathematical models
【单选题】What can be inferred from the passage, according to the passage itself?
A.
The book is still a controversial topic.
B.
The book enjoys high popularity among critics.
C.
The book is a fierce attack on racism.
D.
The hook advocates racism by itself.