A civil engineer has been asked to design a drainage system to reduce flood damage during the rainy reason. She produced a fancy design with a triangular cross section as shown in Figure 2. Two months after the structure was completed, there was a heavy rainfall and water gushed into the drain at the rate of 5m3/s. If the drain is 10m deep, 50m long and 8m wide across the top, at what rate is the depth of the water increasing at the instant that the water depth is 6m?

Question 2 [20 marks] A civil engineer has been asked to design a drainage system to reduce flood damage during the rainy reason. She produced a fancy design with a triangular cross section as shown in Figure 2. Two months after the structure was completed, there was a heavy rainfall and water gushed into the drain at the rate of 5m/s. If the drain is 10m deep, 50m long and 8m wide across the top, at what rate is the depth of the water increasing at the instant that the water depth is 6m? 8m 50m 10m Figure 2: Drainage system.