Short Answer TypeA hemispherical bowl made of brass has inner diameter 10.5 cm. Find the cost of tin-plating it on the inside at the rate of ` 16 per 100 cm2.
A right circular cylinder just encloses a sphere of radius r. Find
(i) surface area of the sphere,
(ii) curved surface area of the cylinder,
(iii) ratio of the areas obtained in (i) and (ii).
Surface area of sphere of radius 5 cm = 4π (5)2 cm2
Area of the curved surface of cone of radius 4 cm = π(4) l cm2 where I cm is the slant height of the cone.
According to the question,
4
(5)2 = 5[
(4)l}
l = 5 cm
r2 + h2 = 25 
(4)2 + h2 = 25
16 + h2 + 25 
h2 = 9
h = 3
Hence, the height of the cone is 3 cm.
= 3.14)
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