High School Physics

Numericals on Density & Relative Density Class 9

This post is on Numericals on Density & Relative Density for Class 9.

Formulas Used

Mass = Volume x density

Volume = mass/density

Density = mass/volume

Relative density RD of a substance = mass of the substance/mass of water of the same volume

Relative density RD of a substance = density of the substance/density of water

Numericals on density and relative density [for class 9] – solved

1] Relative density of gold is 19.3. The density of water is 103 kg/m3. What is the density of gold in kg/m3?

Solution:

Given:
The relative density of gold is 19.3.
The density of water is 103 kg/m3

Relative density of gold = density of gold/density of water
=> density of gold = Relative density of gold x density of water
So, the density of gold = 19.3 x 103 kg/m3

2] Mass of 0.025 m3 of Aluminium is 67 kg. Calculate the density of Aluminium.

Solution:

Given,
Mass of Aluminium = 67 kg
Volume of Aluminium = 0.025 m3

So, the Density of Aluminium = mass/volume = 67/0.025 = 2680 kg/m3