question_answer

The length, breadth and height of a cuboidal reservoir is 7 m, 6 m and 15m respectively. 8400L of water is pumped out from the reservoir. Find the fall in the water level in the reservoir.

Answer:

Here, l = 7 m, b = 6 m, h = 15 m

Volume of cuboid \[=\text{ }l\times b\times h\]

\[=\text{ }7\times 6\times 15\]

\[=\text{ }630\text{ }{{m}^{3}}\]

Since,  \[1\text{ }{{m}^{3}}\text{ }=\text{ }1000\text{ }L\]

\[\therefore \] Capacity of water in reservoir \[=630\times 1000\]

= 630000 L

Since, 8400 L water 5 pumped out

\[\therefore \]Water left in reservoir \[=\text{ }6300008400\]

= 621600 L

\[=\text{ }621.6\text{ }{{m}^{3}}\]

\[Water\text{ }level\text{ }=\frac{Volume}{Base\text{ }Area}\]

\[=\frac{621.6}{7\times 6}\]

= 14.8 m

Fall in water level \[=\text{ }15\text{ }\text{ }14.8\]

= 0.2 m or 20 cm