A hollow sphere of internal and external radii of 2cm and 4 cm

CBSE Class 9 CBSE Class 9 Maths
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1

A hollow sphere of internal and external radii of 2cm and 4 cm is melted into a cone of base radii 4 cm.find height and slant height of the cone?

2

Volume of cone material = Volume of sphere material
⇒ 1/3×π×(r’)2×h = 4/3×π×(R3-r3)
⇒ 42 × h = 4 (43 - 23)
⇒ h = 14 cm
So, l = √(h2 + r’2)
⇒ l = √(142 + 42)
⇒ l = 14.56 cm