A metallic cone having base radius 2.1 cm and height 8.4 cm is melted and moulded into a sphere. The radius of the sphere is
Given: A metallic cone having base radius 2.1 cm and height 8.4 cm
Volume of a cone is given by: 
× π × r2 × h
Let V1 be the volume of the cone
∴ V1 = 
× π × r2 × h
⇒ V1 = 
× π × (2.1)2 × (8.4)
Volume of a sphere is given by: 
× π × r3
Let V2 be the volume of the cone
∴ V1 = 
× π × r3
Here,
V1 = V2
∴ 
× π × (2.1)2 × (8.4) = 
× π × r3
⇒ r3 = 
× π × (2.1)2 × (8.4) × 
= (2.1)3
⇒ r3 = (2.1)3
⇒ r = ∛(2.1)3 = 2.1 cm
∴ Radius of the sphere is 2.1 cm
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