A cylindrical steel rod with a radius of 5 cm is placed in a cylindrical water storage bucket. If you put it all into the water, the water in the bucket will rise by 9cm, if the steel bar in the water is exposed to the water surface by 8cm, then the water in the bucket will drop by 4cm. Find the volume of the bar.
在一个圆柱形储水桶里放入一段半径为5cm的圆柱形钢条．如果把它全部放进水中，桶里的水就上升9cm，如果将水中的钢条露出水面8cm，那么这时桶里的水就下降4cm．求钢条的体积．
<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<gadget id="calculator">5 * 5 * 3.14 * 18</gadget>
<output>1_413</output>

<result>1_413</result>