Question

a spherical having radius 20cm is melted and converted 8 smal spherical ball.Find the radius of ball hence find it surface area

Answer 1

volume of initial spherical ball=8 x volume of final spherical ball
4/3pi.R^3=8 x 4/3pi.r^3
R^3=8r^3
R^3=(2r)^3
R=2r
hence
small ball radius =big ball 's radius/2
=20/2=10cm
now
surface area of small ball= 4pi.r^2
=4 x 22/7 x 10 x 10 cm^2
=1256 cm^2