A square iron block with a side length of 10 cm is forged into a rectangular parallelepiped iron bar with a width of 5 cm and a height of 10 cm. How long is the iron bar in cm? First write down the corresponding quantitative relationship, and then use the equation to solve it.
把一块棱长10cm的正方体铁块，锻造成宽5cm，高10cm的长方体铁条，这块铁条长多少cm？先写出相应的数量关系式，再用方程解．
<gadget id="calculator">10 * 10 * 10</gadget>
<output>1_000</output>

<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<gadget id="calculator">1_000 / 50</gadget>
<output>20</output>

<result>20</result>