(a)
(i) Define relative density.

(ii) A piece of stone weighs 3.6 N in air, 2.6 N in water, and 1.6 N in kerosene. Determine the relative density of the kerosene.



Answer :

Sure, let's tackle this problem step by step.

### (i) Definition of Relative Density
Relative density (also known as specific gravity) is a dimensionless quantity that is defined as the ratio of the density of a substance to the density of a reference substance. For most purposes, the reference substance is water. So, relative density can be expressed mathematically as:

[tex]\[ \text{Relative Density} = \frac{\text{Density of the substance}}{\text{Density of water}} \][/tex]

### (ii) Determining the Relative Density of Kerosene

We have the following information:
1. Weight of the stone in air: 3.6 N
2. Weight of the stone in water: 2.6 N
3. Weight of the stone in kerosene: 1.6 N

#### Step-by-Step Solution:

1. Calculate the buoyant force in water:
The buoyant force experienced by the stone when immersed in water can be found by the difference in weight of the stone in air and in water.

[tex]\[ \text{Buoyant Force in Water} = \text{Weight in Air} - \text{Weight in Water} \][/tex]

Substituting the given values:

[tex]\[ \text{Buoyant Force in Water} = 3.6 \text{ N} - 2.6 \text{ N} = 1.0 \text{ N} \][/tex]

2. Calculate the buoyant force in kerosene:
Similarly, the buoyant force in kerosene can be found by the difference in weight of the stone in air and in kerosene.

[tex]\[ \text{Buoyant Force in Kerosene} = \text{Weight in Air} - \text{Weight in Kerosene} \][/tex]

Substituting the given values:

[tex]\[ \text{Buoyant Force in Kerosene} = 3.6 \text{ N} - 1.6 \text{ N} = 2.0 \text{ N} \][/tex]

3. Determine the relative density of the kerosene:
The relative density of the kerosene can be found by dividing the buoyant force in kerosene by the buoyant force in water.

[tex]\[ \text{Relative Density of Kerosene} = \frac{\text{Buoyant Force in Kerosene}}{\text{Buoyant Force in Water}} \][/tex]

Substituting the calculated values:

[tex]\[ \text{Relative Density of Kerosene} = \frac{2.0 \text{ N}}{1.0 \text{ N}} = 2.0 \][/tex]

So, the relative density of kerosene is 2.0.