Question

find 1)the LSA of closed cylindrical petrol tank that is 4.2m in diameter and 4.5m high. 2) How much steel was actualy used was wasted in making the tank

Answer 1

lateral surface area of cylindrical petrol tank=2.pi.r.h
=2 x 22/7 x (4.2/2) x (4.5) m^2
=44 x (0.3) x (4.5) m^2
=59.4 m^2

area of total steel used by forming petrol tank =2.pi.r.h +pi.r^2+pi.r^2
=2pi.r (h+r)
=2 x 22/7 x (2.1) x (4.5+2.1)
=44 x (0.3) x (6.6) m^2
=87.12 m^2