If a cylindrical piece of wood with a length of 1 meter is cut in half along its diameter, the surface area is increased by 40 square decimeters, what is the volume of this piece of wood in cubic decimeters?
把一根长1米圆柱形的木料沿直径平均切成两半，表面积增加了40平方分米，这根木料的体积是多少立方分米．
<gadget id="calculator">3.14 * 1 * 10</gadget>
<output>31.4</output>

<result>31.4</result>