Question 9 A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in figure. If the height of the cylinder is 10 cm, and its base is of radius 3.5 cm, find the total surface area of the article.
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Solution
Radius = 3.5 cm, height = 10 cm Total surface area of structure = Curved surface area of cylinder + Curved surface area of two hemispheres Curved surface area of cylinder =2πrh =2π×3.5×10 =70πcm2 Surface area of sphere =4πr2 =4π×3.52 =49π Total surface area =70π+49π =119π =119×227=374cm2