Final answer:
To find the speed of water with a given flow rate and cross-sectional area, convert the area to the same units as the flow rate, then use the continuity equation. For this question, after unit conversion, the speed of water is found to be 40.4 m/s.
Step-by-step explanation:
To calculate the speed of the water given the flow rate and cross-sectional area, you can use the continuity equation for fluids. This states that the flow rate (Q) is equal to the cross-sectional area (A) multiplied by the velocity (v) of the fluid. The formula is written as Q = A * v. To solve for v, rearrange the equation to v = Q / A.
In this scenario, the flow rate (Q) is given as 15 m³/s, and the cross-sectional area (A) is 4 square feet. However, we first need to convert the area from square feet to square meters since the flow rate is given in cubic meters per second. There are approximately 0.0929 square meters in a square foot, so the area in square meters is 4 * 0.0929 = 0.3716 m².
Now we have all the values in compatible units; we can insert them into the equation to find the velocity of the water: v = 15 m³/s / 0.3716 m² = 40.4 m/s to one decimal place.