Q9 of 37 Page 195

Volume of a sphere varies directly with the cube of its radius. Three solid spheres having length of and metre diameter are melted and a new solid sphere is formed. Let us find the length of diameter of the new sphere. [let us consider that the volume of sphere remains same before and after melting]

Given:

Radius of first sphere =


Radius of second sphere =


Radius of third sphere =


Let volume is v and radius is r


Acc . to given condition:


V ∝ r3


V = kr3


Volume of sphere of radius 3/4 m is =


Volume of sphere of radius 1 m is = k (1)3 = 1k


Volume of sphere of radius 5/4m is =


Total volume will be :



If the radius of new sphere is R





Diameter of new sphere will be = 2R = 3 m


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