Question

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 gram per centimetre cube

Answer 1

diameter => 4.2 cm. therefore radius => 2.1cm
therefore volume => 4/3*22/7*2.1*2.1*2.1
=>38.8cm3
therefore => mass = density * volume
=> mass => 8.9*38.8
=>345.3 grams

Answer 2

$\huge{\mathcal{Hi\: there!}}$

_______________________

Given :

Diameter of ball = 4.2 cm.

∴ Radius = 4.2 / 2 = 2.1 cm.

Volume of ball = $\frac{4}{3}$ π r³

$\mathsf{⇒ \frac{4}{3} \times \frac{22}{7} \times \frac{21}{10} \times \frac{21}{10} \times \frac{21}{10}} \\ \\ \mathsf{⇒ \frac{38808}{1000}} \\ \\ \mathsf{ ⇒38.808 \: cm {}^{3} }$

∴ Mass = Volume × Density

Density of metal is 8.9 g per cm³

∴ Mass of ball = ( 38.808 × 8.9 ) g

⇒ Mass of ball = 345. 3912 g.

_______________________

Thanks for the question !

☺️❤️☺️❤️☺️