Question

radius of an iron sphere is 0.21 cm . if density of iron is 7.80 g / cc, calculate its mass

Answer 1

Volume of the Sphere is 4/3πr^3

So, Volume = 4/3 × 22/7 × (.21)^3 or, .0388 cm^3


Mass = Density × Volume

So, The answer = 7.8 × .0388 or, .3026 g

Now you got the answer:))

Answer 2

Hi there !!

Radius = r = 0.21cm

Density = 7.80 g/ cm³

Volume of a sphere = 4/3πr³
                                = 4/3 × 22/7 × 0.21 × 0.21 × 0.21
                                = 0.38808 cm ³ 

Density = Mass ÷ Volume

Mass = Density × Volume 
          = 7.80 ×  0.38808
          = 3.02 grams [ approx.]