A solid is composed of a cylinder with hemispherical ends. If the whole height of the solid is 100cm and the diameter of cylindrical part and the hemispherical ends is 28cm, find the cost of polishing the surface of the solid at the rate of 5 paise per sq cm.

Asked by Shantanu | 15th Feb, 2012, 08:19: PM

Expert Answer:

In the given solid height of cylinder = 100 - 2{radius of hemisphere} = 100 - 28 = 72
CSA of the solid = CSA of cylinder + CSA of both hemispheres
= 2*22/7*14*72 + 2 { 2*22/7*14*14 }
= 8800cm2
Cost = 8800 * .05 = Rs 440

Answered by  | 16th Feb, 2012, 10:19: AM

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