Question

A rectangular block of lead measures 20.0 mm x 30.0 mm x 45.0 mm. If the only density of lead is 11.34 g/cm3, calculate the mass of the block.

Answer 1

The formula of density is:

$density = \frac{mass}{volume}$  - (1)

Volume of the block = $20.0 mm\times 30.0 mm \times 45.0 mm$

Since, $1 mm = 0.1 cm$

So, volume of the block = $2.0 cm\times 3.0 cm \times 4.5 cm = 27 cm^{3}$

Density of the block = $11.34 g/cm^{3}$ (given)

Substituting the values in formula 1:

$11.34 g/cm^{3} = \frac{mass}{27 cm^{3}}$

$mass= 27 cm^{3}\times 11.34 g/cm^{3}$

$mass= 306.18 g$

Hence, the mass of the block is $mass= 306.18 g$.