Question

The capacity of a closed cylindrical vessel of height 1 m is 15.4 litres. Find the area of the metal sheet needed to make it.

Answer 1

height of the cylinder =1m

capacity of the cylinder=volume of the cylinder=15.4 litres

=15400 cubic cm

=0.0154 m sq.

so,$\pi r^2$h =0.0154 m sq.

22/7 x $r^2$ x 1=0.0154

$r^2$ =0.0154x 7/22

r2=0.0049

r=0.07

so the total surface area =2rh+2r2

=2r(r+h)

=2x 22/7x0.07(0.07+1)

=0.44x1.07

=0.4708 m sq.