The volume of a cistern is 15.7m**3. There is a water inlet pipe with an inner diameter of 2 cm above the cistern. After turning on the faucet, the flow rate of water is 10 m/min. How many minutes will it take to fill the empty cistern with water?
一个蓄水池的容积是15.7m**3，水池上方有一个内直径是2厘米的进水管，打开水龙头后，水的流速是10米/分，多少分钟后能将空水池注满水？
<gadget id="calculator">0.02 / 2</gadget>
<output>0.01</output>

<gadget id="calculator">0.01 ** 2</gadget>
<output>0.0001</output>

<gadget id="calculator">3.14 * 0.0001 * 10</gadget>
<output>0.00314</output>

<gadget id="calculator">15.7 / 0.00314</gadget>
<output>5_000</output>

<result>5_000</result>