A rocket is in the form of a circular cylinder closed at the lower and a cone of the same radius is attached to the top. The radius of the cylinder is 2.5 m, its height is 21 m and the slant height of the cone is 8 m. Calculate the total surface area of the rocket.
The rocket is in the form of cylinder closed at the bottom and cone on top.
Height of cylindrical part rocket = h = 21 m
Base radius of rocket = r = 2.5 m
Surface Area of cylindrical part of rocket = 2πrh + πr2
= 2 × 22/7 × 2.5 × 21 + 22/7 × 2.5 × 2.5 m2
= 330 + 19.64 m2 = 349.64 m2
Slant height of cone = l = 8 m
Surface Area of conical part of the rocket = πrl
= 22/7 × 2.5 × 8 m2
= 62.86 m2
Total surface area of the rocket = Surface Area of cylindrical part of rocket + Surface Area of conical part of rocket
Total surface area of the rocket = 349.64 + 62.86 m2 = 412.5 m2