There is a conical rubble pile with a circumference of 12.56 meters and a height of 0.9 meters. If each cubic meter of rubble weighs 2 tons, how many tons does this pile of rubble weigh?
有一个近似于圆锥形的碎石堆，底面周长是12.56米，高是0.9米，如果每立方米碎石重2吨，这堆碎石大约重多少吨？
<result>5.736</result>