s cmot A shuttlecock used for playing badminton has the shapea frustum of a cone mounted on a hemisphere as shownthe figure. The external diameters of the frustum are 5 em andcm and the height of the entire shuttlecock is 7 cm. Finexternal surface area.1 cmICBSE Sample Paperl iAns. 74.26 cm2approx.)

s cmot A shuttlecock used for playing badminton has the shapea frustum

1.	s cmot A shuttlecock used for playing badminton has the shapea frustum of a cone mounted on a hemisphere as shownthe figure. The external diameters of the frustum are 5 em andcm and the height of the entire shuttlecock is 7 cm. Finexternal surface area.1 cmICBSE Sample Paperl iAns. 74.26 cm2approx.)
Answer» Given:r1= 1 cm,r2= 2.5 cm,h= 6 cml = √h² + (r2-r1)²= √(6)² + (2.5-1)² cm= √36 + 2.25 cm= √38.25 cm= 6.18cmSo,External Surface area = (curved surface area of frustum) + (curved surface area of hemisphere)= 22/7(r1+r2)l +2.22/7.r1= 22/7 [(1+2.5)6.18 + 2×(1)²] cm²= 22/7 (3.5 × 6.18 +2) cm²= 22/7 (21.63+2) cm²= 22/7 × 23.63 cm²= 519.86/7 cm²= 74.26 cm²