Question

water is flowing at the rate of 15 km/h through a pipe of diameter 14cm into a cuboidal pond which is 50m long and 44m wide.in which time will the level of water in the pond rise by 21cm?

Answer 1

Given: speed of water = 15km/hr =250km/min

Now let the time in which water level in pond rise to 21 cm =x min

Length of water in pipe in x min =250*x=250x

Diameter of pipe =7cm=0.07m

Level rises in pond =21cm =0.21m

Volume of water in pipe in x min = volume of water in pond

22/7*0.07*0.07*250x = 50*44*0.21

3.85x = 462

x=120min=2hr

Hence time taken is 2 hr

Answer 2

Step-by-step explanation:

Answer:

→ Time = 2 hours .

Step-by-step explanation:

Suppose, the level of water in the pond rises by 21 cm in 'x' hours.

→ Speed of water flowing through a pipe = 15 km/hr .

→ Diameter of the pipe = 14/100 m .

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

∵ Volume of water flowing out of the pipe in 1 hour

= πr²h .

= (22/7) x (7/100) x (7/100) x 15000 .

= 231 m³ .

→

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

∵ Volume of water in the cuboidal pond = lbh .

= 50 x 44 x (21/100) .

= 462 m³ .

∵ Volume of water flowing out of the pipe in 'x' hours = Volume of water in the cuboidal pond raised by 21 cm .

∵ 231x = 462 .

⇒ x = $\frac{462}{231}$

.

∴ x = 2 .

Therefore, the required time is 2 hours