A hemispherical tank is made up of an iron sheet 1 cm thick. If the inner radius is 1 m, then find the volume of the iron used to make the tank
Inner radius (r1) = 1 m
External radius (r2) = (1 + 0.1) cm
= 1.01 cm
Volume = external volume – inner volume
= 
πr23 - 
πr13
= 
π (r23 – r13)
= 
* 
* [(1.01)3 – (1)3]
= 
* 0.030301
= 0.06348 m3 (Approx)
22