What are the correct densities of water?

The correct densities of water are indeed 1000 kg/m³ and 62.4 lb/ft³. This value represents the mass of water per unit volume, which is a standard measurement used in various fields including plumbing, engineering, and environmental science. At a temperature of 4°C, water reaches its maximum density, making these values essential for calculations related to buoyancy, fluid dynamics, and hydraulic systems.

Understanding the density of water is crucial for plumbers, as it affects how water behaves in pipes and fixtures, influences the sizing of piping systems, and is vital for calculating the required water pressure for efficient plumbing systems.

The other options provided represent densities that do not apply to water at standard conditions, as they are either too low or too high compared to the recognized standard density of pure water. Thus, option A stands out as the accurate representation of water's density under normal conditions.