A sphere of radius `100mm` shrinks to radius 98mm, then the approximate decrease in its volume is (a)`12000pim m^3` (b) `80000 pim m^3` (C) `8000pim m^3` (d) `120pim m^3`

Explanation

`v= (4/3 pi r^3)`

`r= 100 mm`

`del v = (4/3) pi (3r^2) del r `

`= 4 pi r^2 del r`

`del r = 98-100 = -2`

`r= 100mm`

`del v = 4 pi r (100)^2 xx (-2) `

`= -80000 pi mm^3`

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