Physics Lesson 13.2.4 - Volume Thermal Expansion and Contraction

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Welcome to our Physics lesson on Volume Thermal Expansion and Contraction, this is the fourth lesson of our suite of physics lessons covering the topic of Thermal Expansion, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.

Volume Thermal Expansion and Contraction

As stated earlier, when an object expands or contract due to the change in temperature, it experiences a volume thermal expansion or contraction. Since objects extend in three dimensions in space, they experience a linear expansion or contraction for each dimension. This mean the coefficient of volume expansion or contraction γ is triple the corresponding linear expansion coefficient α, i.e.

γ = 3 × α

For example, given that the linear thermal expansion of mercury is α = 61 × 10^-6 K-1, its corresponding coefficient of volume thermal expansion is

γ = 3 × α
= 3 × 61 × 10^-6 K^-1
= 183 × 10^-6 K^-1

In this way, if an object has a volume V⁰ at temperature T₀, its volume V at another temperature T becomes

V = V₀ × (1 + γ × ∆T)

Example 3

A plastic object of volume 40 cm³ is brought near a heat source in which the air temperature is 80°C. Given that the linear expansion coefficient of plastics at 20°C is 100 × 10^-6 K-1, calculate the final volume of the object after experiencing thermal expansion.

Solution 3

We have the following clues:

V⁰ = 40 cm³ = 40 × 10^-6 m³ = 4 × 10^-5 m³
t⁰ = 20°C
t = 80°C
α = 100 × 10^-6 K^-1 = 10^-4 K^-1
V = ?

We have:

V = V₀ × (1 + γ × ∆T)
= V₀ × [1 + 3α × (t - t₀)]
= 4 × 10^-5 × [1 + 3 × 10^-4 × (80 - 20)]
= 4 × 10^-5 × (1 + 3 × 10^-4 × 60)
= 4 × 10^-5 × (1 + 180 × 10^-4 )
= 4 × 10^-5 × (1 + 0.0180)
= 4 × 10^-5 × 1.018
= 4.072 × 10^-5 m²
= 40.72 cm³

This means the object's volume increases by 0.72 cm³ during the given process of thermal expansion.

You have reached the end of Physics lesson 13.2.4 Volume Thermal Expansion and Contraction. There are 7 lessons in this physics tutorial covering Thermal Expansion, you can access all the lessons from this tutorial below.

More Thermal Expansion Lessons and Learning Resources

Thermodynamics Learning Material
Tutorial ID	Physics Tutorial Title	Revision Notes	Revision Questions
13.2	Thermal Expansion
Lesson ID	Physics Lesson Title	Lesson	Video Lesson
13.2.1	What is Thermal Expansion and Thermal Contraction?
13.2.2	Linear Thermal Expansion and Contraction
13.2.3	Area Thermal Expansion and Contraction
13.2.4	Volume Thermal Expansion and Contraction
13.2.5	Thermal Expansion and Contraction in Daily Life
13.2.6	Bimetallic Strip. Thermostat
13.2.7	Types of Thermometers

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Volume Feedback. Helps other - Leave a rating for this volume (see below)
Thermodynamics Physics tutorial: Thermal Expansion. Read the Thermal Expansion physics tutorial and build your physics knowledge of Thermodynamics
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Thermodynamics Practice Questions: Thermal Expansion. Test and improve your knowledge of Thermal Expansion with example questins and answers
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Continuing learning thermodynamics - read our next physics tutorial: Absorption of Heat

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