Saved Bookmarks
| 1. |
A Shuttle cock used for playing badminton has the shape of frustrum ofa cone mounted on the hemisphere. The external diameters of thetum are 5cm and 2cm and height of the entire shuttle cock is 7 cm. Findthe external surface areafrus- |
|
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 thanks |
|