AMC8 2002

AMC8 2002 · Q6

AMC8 2002 · Q6. It mainly tests Rates (speed).

A birdbath is designed to overflow so that it will be self-cleaning. Water flows in at the rate of 20 milliliters per minute and drains at the rate of 18 milliliters per minute. One of these graphs shows the volume of water in the birdbath during the filling time and continuing into the overflow time. Which one is it?

一个鸟浴设计成会溢水以实现自清洁。水以每分钟20毫升的速率流入，以每分钟18毫升的速率排出。其中一个图表显示了鸟浴在填充时间及溢水时间的水量变化。哪一个是正确的？

(A)

(B)

(C)

(D)

(E)

Answer

Correct choice: (A)

正确答案：（A）

Solution

Initially, volume increases with time as shown by graphs A, C, and E. But once the birdbath is full, the volume remains constant as the birdbath overflows. Only graph A shows both features.

最初，水量随时间增加，如图A、C和E所示。但一旦鸟浴满了，水量保持恒定，因为鸟浴溢水。只有图A显示了这两个特征。

Topics

AR.007 Rates (speed)