Final answer:
The surface area of the open tank is 74.8 square meters.
Step-by-step explanation:
The surface area of a tank is the sum of the areas of all its faces. To calculate the surface area of the open tank, we need the dimensions of the tank's base and its height.
From the given information, it seems that the tank has a rectangular base with dimensions of 2.8m by 3m. Assuming the tank is open at the top, we only need to calculate the surface area of the four vertical faces. The top face is not included in the surface area calculation.
The surface area formula for a rectangular tank is A = 2(lw + lh + wh), where l is the length, w is the width, and h is the height. Using the given dimensions, we can substitute the values into the formula:
A = 2(2.8m * 3m + 2.8m * 5m + 3m * 5m) = 2(8.4m² + 14m² + 15m²) = 2(37.4m²) = 74.8m²
Therefore, the surface area of the open tank is 74.8 square meters.