Question

Two spheres of same metal weigh 1 kg and 7kg if radius of smaller is 3cm then find diameter of larger

Answer 1

Given  : Two spheres of the Same metal weigh 1 kg and 7 kg . The radius of the smaller sphere is 3 cm .

We know volume of sphere  =  4 π r33 , So

Volume of small sphere ( With radius of 3 cm ) =  4 ×π ×333 = 4 ×π × 273 = 4 ×π ×9 =36 π cm3
Mass ( Weight ) of small sphere  =  1 kg 

We know :  Density = MassVolume , So

Density of small sphere = 136 π kg/cm3
Then ,

Mass of new formed sphere  =  1 + 7   =  8  kg

Let , Radius of new sphere =  r , So  volume of new sphere  =  4 π r33
And

Density of new sphere = 84 π  r33  = 2π  r33 = 6π  r3 kg/cm3
As here given : Both sphere formed by same metal so density will be same .

Therefore,

6π r3 = 136 π⇒6r3 = 136⇒r3 = 216⇒r3 = 63⇒r = 6
So,

Radius of new sphere = 6 cm                                                                 ( Ans )

I hope this helps you .
mark me as Brainlist .
❤️❤️

Answer 2

Answer:

Step-by-step explanation: