A water tank is the form of a cube of side 2 m. It has an inlet in the shape of a circle with radius 3.5 cm. How long will it take to fill the tank (approximately), if the water is flowing at a speed of 2 m/s?

Correct option is B

Given:

Side of tank of cube shape = 2m

Radius of inlet = 3.5cm

Rate of water flowing = 2m/s

Formula Used:​

Volume of cube = $$a^3$$​​

Volume cylinder = $$\pi r^2 h$$​​

Solution:

Total volume of tank =$$(2)^3 = 8m^3$$​​

Total volume of water flowing at 2 m/sec will volume of cylinder

Here radius in m = $$\frac{3.5}{100} = 0.035m$$​​

Volume per second flowing through pipe = $$\pi (0.035)^2 (2) = 0.0077m^3$$​​

Time required to fill the tank = $$\frac{8}{0.0077}$$​ = 1038.96 seconds

Time in minutes = $$\frac{1038.96}{60}$$​ = 17.3 minutes