In a cylindrical container with a bottom area of 300 square centimeters (there is some water in the container), a cylindrical iron rod with a height of 60 cm and a bottom area of 100 square centimeters is placed upright (the bottom surface of the iron rod is close to the bottom surface of the container) , At this time, the water depth in the container is 50 cm. Now lift the iron bar slightly to the top, so that the bottom surface of the iron bar is 10 cm away from the bottom of the container. How many centimeters is the wetted part of the cylindrical iron bar exposed to the water surface?
在底面积是300平方厘米的圆柱形容器(容器中有一些水)里，直立放着一个高是60厘米，底面积是100平方厘米的圆柱形铁棍(铁棍底面与容器底面紧贴)，这时容器里的水深50厘米，现在把铁棍轻轻地向正上方提起，使铁棍的底面距容器底10厘米，露出水面的圆柱形铁棍浸湿部分长多少厘米？
<gadget id="calculator">300 - 100</gadget>
<output>200</output>

<gadget id="calculator">10 / 200</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">100 * (1/20)</gadget>
<output>5</output>

<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<result>15</result>