There are two cylindrical containers A and B. Initially, container A is filled with 2000mL of water, and container B is empty. Now, water is poured into the two containers at a flow rate of 400mL per minute. After 4 minutes, the water surface height of the two volumes Equal, given that the radius of the bottom surface of volume A is 4cm, what is the radius of the bottom surface of container B?
有甲、乙两个圆柱形容器，最初甲容器里装有2000mL的水，乙容器是空的，现在往两个容器里以每分钟400mL的流量注水，4分钟后，两个容积的水面高度相等，已知甲容积的底面半径为4cm，求乙容器的底面半径是多少？
<gadget id="calculator">8 / 3</gadget>
<output>8/3 = around 2.666667</output>

<result>8/3 = around 2.666667</result>