Question

A hollow hemispherical bowl is made of silver with its outer radius 8cm and inner radius 4 cm respectively.
the bowl is melted to form a solid right Circular cone of radius 8 cm. The height of the cone formed is
a)7cm
b) 9 cm
c) 12cm
d) 14 cm
​

Answer 1

As we have to find the height of the cone we first have to find the volume of cone

so,

vol.of cone = Vol.of the hemispherical bowl

vol. of bowl= 2/3 π R³ - 2/3 π r³

= 2/3 π (R³ - r ³)

= 2/3 π (8³-4³)

= 2/3 π (512-64)

= 2/3 π × 448 cm³

vol. of cone = 1/3 π r²h

2/3 π × 448 = 1/3 π r²h

2×448/64=h

*h= 14 cm*

Answer 2

14cm is the correct answer.