问题
选择题
—I don't know what I should have done without your help.
— .[ ]
A. With pleasure
B. My pleasure
C. Not quite
D. Not in the least
答案
答案:B
—I don't know what I should have done without your help.
— .[ ]
A. With pleasure
B. My pleasure
C. Not quite
D. Not in the least
答案:B
下表是某同学为“探究弹力与弹簧伸长量的关系”所测的几组数据:
弹力F/N | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 |
弹簧的伸长x/cm | 2.6 | 5.0 | 7.2 | 9.8 | 12.4 |
(2)写出图线所代表的函数式(x用m为单位):______;
(3)写出函数表达式中常数的物理意义______;
(4)若弹簧的原长为40cm,并且以弹簧的总长度l为自变量,写出函数表达式(以N和m为单位):______.