A hollow metallic sphere of external and internal diameters 8cm and 4cm respectively is
melted to form a solid cone of base diameter 8cm. Find the height of the cone.
Answers
•If solid of one shape is converted into solid of another shape, then Total volume of the solid to be converted = Total volume of the solid into which the given solid is to be converted.
Given : Internal diameter of hollow sphere(d)= 4 cm.
Internal radius of hollow sphere (r) = 4/2= 2 cm
external diameter of hollow sphere (D) = 8 cm.
external radius of hollow sphere( R )= 8/2= 4 cm.
Volume of the Hollow sphere = 4/3π(R³ - r³)
Volume of the Hollow sphere = 4/3π(4³ - 2³)
Volume of the Hollow sphere = 4/3π(64 - 8)
Volume of the Hollow sphere = 4/3π(56) cm³
Diameter of the cone(d1) = 8 cm
radius of the cone( r1)= 8/2 = 4 cm
Let the height of the cone be h cm.
Volume of the cone = ⅓ πr1²h
= ⅓ π × 4² × h = 16πh/3
Volume of the cone = Volume of the hollow sphere
16πh/3 = 4/3π(56)
16h = 4 ×56
h = (4 × 56)/16
h = 56/4 = 14 cm
Hence, the height of the cone is 14 cm.
Step-by-step explanation:
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