Final answer:
The possible error of measurement for the height of the iron rod is ±0.01 cm.
Step-by-step explanation:
The possible error of measurement for the height of the iron rod can be determined by considering the precision of the measuring instrument. In this case, we have two types of rulers, one with centimeter markings and the other with millimeter markings. The ruler with millimeter markings is more precise because it allows for measurements to the hundredth digit. However, even with the millimeter ruler, there is still some uncertainty in the measurement. For example, if the rod is reported as 2.55 cm, the hundredths digit is uncertain and could be either 4 or 6.
To determine the possible error, we can consider the range of measurements that are possible. In this case, since the ruler with millimeter markings allows for measurements to the hundredth digit, we can say that the possible error is ±0.01 cm.
Therefore, the possible error of measurement for the height of the iron rod is ±0.01 cm.