Question

A hemispherical tank full of water is emptied by a pipe at the rate of 25/7 litres per second. How much time will it take to empty half the tank, if it is 3m in diameter ?

Answer 1

Diameter = 3m
radius = 3/2 = 1.5 m

$volume= \frac{2}{3} \pi r^3 \\ \\ volume= \frac{2}{3} \times 3.14 \times 1.5^3 = 7.065\ m^3=7065l$

emptying rate = 25/7 l per second
let the time taken to empty half volume = t

[tex] \frac{25}{7} \times t= \frac{1}{2} \times volume\\ \\ t= \frac{1}{2} \times 7065 \times \frac{7}{25} \\ \\ t=\boxed{989\ seconds}[/tex]

Answer 2

Step-by-step explanation:

time is taken 989 second