Question

water is flowing at the rate of 15km hour through a pipe of diameter 14cm into a cuboidal pond
which is 50m long and 44m wide. In what time will the level of water in the pond rise bv 21cm?
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Answer 1

Answer:

Let the level of water in the pond rises by 21 cm in t hours.

Speed of water = 15 km/hr

Diameter of the pipe = 14/100 m

Radius of the pipe (r) = 7/100 m

Volume of water flowing out of the pipe in 1 hour = π r 2 h = (22/7) x (7/100) x (7/100) x 15000 = 231 m3

Volume of water flowing out of the pipe in t hours = 231 t m3.

Volume of water in the cuboidal pond = 50 x 44 x (21/100) = 462 m3 

Volume of water flowing out of the pipe in t hours = Volume of water in the cuboidal pond So, 231 t = 462 t = 2 Thus, the required time is 2 hours.