Thermal Expansion

What is Thermal Expansion?

Thermal expansion is the tendency of matter to change in shape, area, and volume in response to a change in temperature. When substances are heated, they expand, and when they are cooled, they contract.

Types of Thermal Expansion

• Linear Expansion: Change in length of an object when its temperature changes.
• Area Expansion: Change in surface area of an object when its temperature changes.
• Volume Expansion: Change in volume of an object when its temperature changes.

Linear Expansion

Linear expansion refers to the increase in length of a material. It can be calculated using the formula:

$$\Delta L = \alpha L_0 \Delta T$$

• $\Delta L$ = Change in length
• $\alpha$ = Coefficient of linear expansion
• $L_0$ = Original length
• $\Delta T$ = Change in temperature

Area Expansion

Area expansion refers to the increase in surface area of a material. It can be calculated using the formula:

$$\Delta A = 2\alpha A_0 \Delta T$$

• $\Delta A$ = Change in area
• $A_0$ = Original area

Volume Expansion

Volume expansion refers to the increase in volume of a material. It can be calculated using the formula:

$$\Delta V = \beta V_0 \Delta T$$

• $\Delta V$ = Change in volume
• $\beta$ = Coefficient of volume expansion
• $V_0$ = Original volume

Worked Example