The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8.9 g per cm3?
Radius (r) = 2.1 cm
Volume = 
πr3
= 
* 
* (2.1)3
= 38.808 cm3
Density = 
Mass = Density * Volume
= 8.9 * 38.808
= 345.3912 g
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