A cylindrical bucket with a base radius of 40 cm is filled with water, and the water depth is 80 cm. A cone with a base radius of 20 cm is submerged in the water. The water surface rises by 1.5 cm. What is the height of the cone?
一只底面半径为40厘米的圆柱形水桶内盛水，水深80厘米，将一个底面半径20厘米的圆锥体铁块沉没水中，水面上升1.5厘米，圆锥高多少厘米？
<gadget id="calculator">40 ** 2</gadget>
<output>1_600</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<gadget id="calculator">3 / 1_256</gadget>
<output>3/1_256 = around 0.002389</output>

<gadget id="calculator">3.14 * 1_600 * 1.5 * (3/1_256)</gadget>
<output>18</output>

<result>18</result>