A cylindrical glass cylinder with a bottom radius of 2 decimeters contains water 1.5 decimeters deep. A conical piece of iron is placed in the water (completely submerged), and the water rises by 0.5 decimeters. What is the volume of this piece of iron?
一个圆柱形玻璃缸，底面半径为2分米，里面盛有1.5分米深的水，将一块圆锥形铁放入水中(完全浸没)，水面上升0.5分米，这块铁的体积是多少？
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 0.5</gadget>
<output>6.28</output>

<result>6.28</result>