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प्रश्न
A hemispherical tank full of water is emptied by a pipe at the rate of \[\frac{25}{7}\] litres per second. How much time will it take to half-empty the tank, If the tank is 3 metres in diameter?
उत्तर
Volume of half of hemispherical tank
`=2/3pir^3`
`=2/3 xx 22/7 xx (3/2)^3`
` = (49500)/7`ltr.
Amount of water emptied by pipe in 1 sec.`= 25/7`ltr
So, time taken
`=7/25 xx (49500)/7`
` = 1980 sec`
`= (1980)/60 min`
`= 33 min`
To half empty the tank line
` = 33/2`
` = 16.5 min`
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