Half of a tank of length 5 metre , breadth 4 metre and height 2.2 metre , is filled with water How many iron - bullets of radius 5 cm each should be completely immersed into the water of the tank so that the tank full to the brim ?

Explanation

The radius of each iron - bullet = 5 cm
` :. ` the volume of each iron - bullet ` = 4/3 pi xx 5^(3) ` cc
Let the required number of iron - bullets be x
` :.` the total volume of x bullets ` = x xx 4/3 pi xx 5^(3) ` cc
Since half of the tank is filled with water , so the water - level of the tank will be increased ` (2.2)/2 ` m = 1.1 m to be filled to the brim
So , the volume of the raised - water ` = 5 xx 4 xx 1.1 ` cubic - metre
` = 500 xx 400 xx 110 ` cc
As per question , `4/3 xx 22/7 xx 5^(3) xx x = = 500 xx 400 xx 110`
` rArr x = (500 xx 400 xx 110 xx 3 xx 7 )/(4 xx 22 xx 125 ) rArr x = 42000`
Hence the required number of iron - bullets = 42000