Q4 of 48 Page 267

A cylinder of radius 2 cm and height 10 cm is melted into small spherical balls of diameter 1 cm. Find the number of such balls.

Given.


Cylinder of radius 2 cm and height 10 cm


spherical balls of diameter 1 cm


Formula used/Theory.


Volume of cylinder = πr2h


Volume of sphere = πr3


Volume of cylinder = πr2h


= π × (2 cm) 2 × 10 cm


= 40π cm3


Radius of sphere = = 0.5 cm


Volume of sphere = πr3


= π (0.5 cm) 3


= π cm3


**Note we will not put value of π as it will be divided in next step


Number of spherical balls will be dividing the total volume of cylinder by volume of 1 spherical ball


Number of spherical balls = = 240


∴ 240 Spherical balls can be made by melting cylinder


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