Final answer:
To find the irrigation area, we calculate the volume of water flowing through the canal in 30 minutes and divide it by the required irrigation depth of 8cm.
Step-by-step explanation:
The problem concerns the irrigation area that can be covered by water flowing through a canal over a certain period of time. Given that the canal is 30 decimeters (dm) wide and 12 dm deep with water flowing at a velocity of 10 kilometers per hour (km/hr), we need to calculate the volume of water that flows through the canal in 30 minutes to ascertain how much area it can irrigate given an irrigation depth of 8 centimeters (cm).
Firstly, we convert the velocity to meters per second (m/s) and the time to seconds to work in consistent units. We then calculate the flow rate and finally the area irrigated using the volume of water delivered in the given time and the required depth of irrigation. The formula used to calculate the area is:
Area = Volume / Depth
Where volume is flow rate multiplied by time. After finding the total volume, it is divided by the irrigation depth to determine the total area that can be irrigated.