Question

a cylindrical milk steel storage tank has 4.2m as diameter and is 4.5 m high . [a] find quantity of milk it can contain. [b] how much steel sheet was actually used to make this closed tank , if 1/7 of steel sheet was wased in making the tank

Answer 1

Given = diameter = 4.2 m so radius = 2.1 m
              height = 4.5 m 

[a] Quantity of milk it can contain so we need to calculate the volume of the tank
 Volume of cylinder = πr^2h
                                 = 22/7*2.1*2.1*4.5
                                 = 22*0.3*2.1*4.5
                                 = 6.6*9.45
                                 = 62.37 cu. m
[b] how much steel was used so we need to calculate total surface area of the tank
  T.S.A of cylinder = 2πr(r+h)
                              = 2*22/7*2.1(2.1+4.5)
                              = 2*22*0.3(2.1+4.5)
                              = 13.2*6.6
                              = 87.12 sq. m