A cylindrical piece of wood is cut 5 meters, and the cross-sectional diameter is 10 centimeters. Is the volume of the cut section 40 cubic decimeters? Explain by calculation.
一根圆柱形木料，截下5米，量得横截面直径为10厘米，截下这段体积有40立方分米吗？通过计算加以说明．
<result>40</result>