A pile of coal is in the shape of a cone with a base diameter of 4 meters and a height of 1.5 meters. If each cubic meter of coal weighs about 1.4 tons, how many tons does this pile of coal weigh? (retain one decimal place)
一堆煤成圆锥形，底面直径是4米，高是1.5米．若每立方米的煤约重1.4吨，这堆煤约有多少吨？(得数保留一位小数)
<result>8.8</result>