Question

Radius of an iron sphere is 0.21 cm if density of iron is 7.80 g calculate the mass

Answer 1

given: r= 0.21 cm
density of iron= 7.80 g
we know, volume of sphere = 4/3πr^3
therefore, volume=4/3*22/7*21/100*21/100*21/100
volume=4*21*21*21/1000000
=38808*10^-6 cm^3
therfore, density=mass/ volume
mass=density*volume
=7.80**38808*10^-6
= 0.3 g

Answer 2

HI there !

Density = Mass / Volume

Density = 7.8 g/cm³

Radius = r = 0.21 cm

Volume of a sphere = 4/3πr³
                                = 4/3 × 22/7 × (0.21)³
                                = 0.038808 cm³

Mass = Density × Volume
         = 7.8 × 0.038808
         = 0.3027024 grams