Question

A) 0.95
B) 0.85
C) 0.05
D) 195
7) A metallic cone of volume 2136 cm' is recast into a hemisphere. The radius of the hemisphere is
A) 14 cm
B) 7 cm
C) 21 cm D) 3.5 cm​

Answer 1

Step-by-step explanation:

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Q. 1

5.0

( 5 Votes )

A solid metallic hemisphere of radius 8 cm is melted and re-casted into a right circular cone of base radius 6 cm. Determine the height of the cone.

Class 10th

NCERT - Maths Exemplar

12. Surface Areas and Volumes

Answer

For hemisphere,

Radius, r = 8 cm

As we know,

Volume of hemisphere

Where, r = radius of hemisphere

Volume of given hemisphere

For cone that is recast from hemisphere,

Base radius, r = 6 cm

We know that,

volume of cone

Where, r is base radius and h is the height of the cone.

Now,

Volume of cone

As the volume remains same, when a body is reformed to another body

Volume of cylinder = Volume of cone

12πh = 1024π /3

h = 28.44 cm