Question

Find the number of small iron spheres of radius 1.75cm . which are making from melting big iron sphere of radius 3.5cm

Answer 1

Answer:

8

Step-by-step explanation:

given the radius of the big iron sphere is R=3.5cm

and the radius of the small sphere is r=1.75cm

let the number of the small sphere is n

now

       n×4/3πr³ = 4/3πR³

        nr³ =  R³

        n× (1.75)³ = (3.5)³

        n× 5.359375 = 42.875

        n = 42.875/5.359375

         n = 8

Answer 2

Answer :

8

Solution :

Radius of Big iron sphere ( R ) = 3.5 cm

Radius of small iron spheres ( r ) = 1.75 cm

Let the number of small iron spheres be 'n'

Given :-

From a big iron sphere small iron spheres are melted

So, n * Volume of small iron sphere = Volume of big iron sphere

==> n * 4/3 * π * r³ = 4/3 * π * R³

Cancelling 4/3 * π on both sides

==> n * r³ = R³

==> n * 1.75³ = 3.5³

==> n * 1.75 * 1.75 * 1.75 = 3.5 * 3.5 * 3.5

==> n = ( 3.5 * 3.5 * 3.5 ) / ( 1.75 * 1.75 * 1.75 )

==> n = 2 * 2 * 2

==> n = 8

Therefore 8 small iron spheres are melted.