Question

22. A cubic object has sides with lengths of 6.0 cm,

3.0 cm, and 2.0 cm. The mass of the cube
is 162.2 g. What is its density to the correct
number of significant figures?
(1) 0.22 g/cm3 (3) 4.5 g/cm3
(2) 0.2219 g/cm3 (4) 4.505 g/cm3

Answer 1

Answer : The correct option is, (3)
`4.5g/cm^3`

Explanation :

Density : It is defined as the mass contained per unit volume.

Formula used :

`Density=(Mass)/(Volume)`

First we have to calculate the volume of cuboid.

Formula used :

`V=l* b* h`

where,

V = volume of cuboid

l = length of cuboid = 6.0 cm

b = breadth of cuboid = 3.0 cm

h = height of cuboid = 2.0 cm

Now put all the given values in the above formula, we get:

`V=6.0cm* 3.0cm* 2.0cm=36cm^3`

Now we have to calculate the density of cube.

Given :

Mass of cube = 162.2 g

Volume of cube =
`36cm^3`

Now put all the given values in the above formula, we get :

`Density=(162.2g)/(36cm^3)=4.5g/cm^3`

Therefore, the density of cube is
`4.5g/cm^3`

Answer 2

option 4 =4.505 g/cm³

Step-by-step explanation:

Density:

Density is equal to the mass of substance divided by its volume.

Units:

SI unit of density is Kg/m3.

Other units are given below,

g/cm3, g/mL , kg/L

Formula:

D=m/v

D= density

m=mass

V=volume

Symbol:

The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.

Given data:

Mass of cube = 162.2 g

density = ?

Volume = 6cm× 3cm×2cm = 36cm³

Solution:

d= m/v

d = 162.2 g/ 36 cm³

d = 4.505 g/cm³