Question

The diameter of a metallic ball is 4.2cm. What is the mass of a ball, if the density of the metal is 8.9g per cm3

Answer 1

radius of sphere = 2.1 cm

volume of sphere = 4πr³/3

=4*22*21*21*21/3*1000*7

= 38808/1000

= 38.808 cm³

density of ball = 8.9*38.808

= 310.464 per cm³

mark it as a brainliest answer

Answer 2

Given :

• Diameter of ball = 4.2cm

To Find :

• Mass of the ball if the density of metal is 8.9g per cm³.

Solution :

$\longmapsto\tt{Diameter=4.2cm}$

$\longmapsto\tt{Radius=\cancel\dfrac{4.2}{2}=2.1cm}$

Using Formula :

$\longmapsto\tt\boxed{Volume\:of\:Sphere=\dfrac{4}{3}\pi{{r}^{3}}}$

Putting Values :

$\longmapsto\tt{\dfrac{4}{\cancel{3}}\times\dfrac{22}{\cancel{7}}\times\dfrac{\cancel{21}}{10}\times\dfrac{21}{10}\times\dfrac{21}{10}}$

$\longmapsto\tt{\dfrac{38808}{1000}}$

$\longmapsto\tt\bold{38.808g}$

Now :

• Density of metal per m³ = 8.9g

$\longmapsto\tt\bold{Density\:of\:38.808{m}^{3}:-}$

$\longmapsto\tt{8.9\times{38.808}}$

$\longmapsto\tt\bold{345.39g (Approx.)}$