光缆敷设的静态弯曲半径应不小于光缆外径的()倍,施工过程中的动态弯曲半径应不小于()倍。布放光缆时,光缆必须由缆盘()方放出并保持松弛的(弧形)。
参考答案:15;20;上
The overweight adolescent client tells the nurse that he would like to lose weight and asks the nurse’s opinion on how to accomplish his goal. Which of the following suggestions would be most appropriate
A. Exercising more often.B. Severely limiting calorie intake.C. Participating in an adolescent weight-reduction program.D. Cutting clown on sweets and other snacks.
(14分)如图甲所示,在倾角为370的粗糙足够长的斜面的底端,一质量m=1kg可视为质点的滑块压缩一轻弹簧,滑块与弹簧不相连。t=0时释放物块,计算机通过传感器描绘出滑块的速度时间图象如图乙所示,其中oab段为曲线,bc段为直线,在t1=0.1s时滑块已上滑s=0.2m的距离,g取10m/s2。求:
(1)物体与斜面间的动摩擦因数μ的大小;
(2)压缩弹簧时,弹簧具有的弹性势能.