Find the time required to lower the water surface of a rectangular tank of cross sectional area 5000 m 2 from an elevation of 10.20 m to 9.20 m. A rectangular suppressed weir of length 2.0 m with its...

Find the time required to lower the water surface of a rectangular tank of cross sectional area 5000 m²
from an elevation of 10.20 m to 9.20 m. A rectangular suppressed weir of length 2.0 m with its crest at elevation 7.7 m above the datum is used for lowering the water surface (Assume C_d
= 0.62).