Question

A rectangular water tank of base $11m\times 6m$ contains water upto a height of 5 m. If the water in the tank is transferred to a cylindrical tank of radius 3.5 m, find the height of the water level in the tank.

Answer 1

Given, dimensions of base of rectangular tank
$=11m\times 6m$ and
Height of water = 5 m

Volume of the water in rectangular tank
$=l\times b\times h$
$=11\times 6\times 5=330m^3$

Also, given radius of the cylinder tank = 3.5 m

Let the height of water level in the cylindrical tank be h.

Then, volume of the water in cylindrical tank
$=\pi r^{2}h=\pi (3.5{)}^2\times h=\frac{22}{7}\times 3.5\times 3.5\times h=11\times 3.5\times h=38.5h{m}^3$

According to the question.
330 = 38.5 h [ Since, volume of water is same in both tanks]
$h=\frac{330}{38.5}=\frac{3300}{385}=8.57mor8.6m(approx.)$

Hence, the height of water level in cylindrical tank is 8.6 m.