Question

Carry out the following calculation. Express your answer in the correct number of significant figures.

A solid rectangular block has a density of 2.6 g/cm3. The block measures 1.8 cm by 4.0 cm by 2.3 cm. What is the mass, in g, of the block?

Answer 1

43.1 g

Step-by-step explanation:

Density, d is defined as the mass per unit volume of an object. Density is therefore expressed as

d=m/v

Here, m is mass and v is the volume

Making mass the subject of the formula

Mass, m=dv

The volume, v is given by

V=lwh

Substituting lwh for v in the equation for mass then mass, m=dlwh

Substituting 2.6 g/cm3 for d, 4.0 cm for l, 1.8 m for w and 2.3 for h then the mass of the block will be

M=2.6*4*1.8*2.3=43.056 g

Expressing it in 1 decimal place, mass is approximately 43.1 g