A wooden article was made by scooping out a hemisphere from each end of a solid

Mensuration (10)

A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in Fig. 3. 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.

Answer

Total surface Area of article = CSA of cylinder + CSA of 2 hemispheres

CSA of cylinder = 2πrh 

= $ 2\times \frac{22}{7}\times 3.5 \times 10 $

= 220 cm²

Surface Area of two hemispherical scoops  

=  $4 \times\frac{22}{7} \times 3.5 \times 3.5$

= 154 cm²

Total surface Area of article = 220 + 154 

= 374 cm²

• Exam Year: 2018