Given data
*The given power of the pump is P = 50 kW = 50 × 10^3 W
*The given depth is h = 50 m
*The given time is t = 1.4 min = (1.4 × 60) = 84 s
The mass is calculated by the power formula as
[tex]\begin{gathered} P=\frac{W}{t} \\ P=\frac{mgh}{t} \end{gathered}[/tex]Substitute the known values in the above expression as
[tex]\begin{gathered} 50\times10^3=\frac{m\times9.8\times50}{84} \\ m=8571.42\text{ kg} \end{gathered}[/tex]Hence, the mass of the water is m = 8571.42 kg