Rebecca consumes both iced tea and coffee. Iced tea is priced at $1.50 per bottle and coffee at $2.00 per 16-ounce cup. Which of the following marginal utility pairs is consistent with Rebecca's consumer equilibrium at these prices?
【简答题】在用电火花计时器 “ 研究匀变速直线运动 ” 的实验中,如图所示是一条记录小车运动情况的纸带,图中 A 、 B 、 C 、 D 、 E 为相邻的计数点,相邻计数点间还有四个点未画出. ( 电源频率为 50 Hz) (1) 根据运动学有关公式可求得: v B = 1.38 m /s , v C = ________m/s , v D = 3.90 m /s ; ( 保留三位有效数字 ) (2) ...