question_answer

The length, breadth and height of a cuboidal reservoir is 7 m, 6 m and 15 m 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 =\[l\times b\times h\]

\[=7\times 6\times 15\]

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

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

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

= 630000 L

Since, 8400 L water 5 pumped our

\[\therefore \] Water left in reservoir \[=\text{ }630000-8400\]

= 621600 L

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

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

\[=\frac{624.6}{7\times 6}\]

= 14.8 m

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

= 0.2 m or 20 cm