Question : The total surface area of a solid metallic hemisphere is 462 cm2. This is melted and moulded into a right circular cone. If the radius of the base of the cone is the same as that of the hemisphere, then its height is: (use
Option 1: 14 cm
Option 2: 7 cm
Option 3: 21 cm
Option 4: 28 cm
Correct Answer: 14 cm
Solution :
The total surface area of a solid metallic hemisphere = 462 cm
2
Let the radius of the hemisphere be
So,
⇒
So, the volume of the hemisphere =
Now, the radius of hemisphere (
So, The volume of the cone = volume of the hemisphere
⇒
⇒
Hence, the correct answer is 14 cm.
