The expansion of the length of an iron bridge, $\Delta l$, during hot summers can be described using the linear thermal expansion formula. This relationship can be expressed as:

$\Delta l = \alpha l_0 \Delta T$

where:

• $\Delta l$ is the change in length of the bridge.
• $\alpha$ is the coefficient of linear expansion for iron.
• $l_0$ is the original length of the bridge at 0°C.
• $\Delta T$ is the change in temperature.

This formula indicates that the change in length is directly proportional to both the original length and the change in temperature.

Would you like more details or have any questions?

Here are 5 related questions you can ask:

1. How do you calculate the coefficient of linear expansion?
2. What are typical values of the coefficient of linear expansion for common materials?
3. How does the expansion affect the structural integrity of bridges?
4. Can this formula be applied to other materials besides iron?
5. How do engineers mitigate the effects of thermal expansion in large structures?

Tip: When solving thermal expansion problems, always ensure the temperature change ($\Delta T$) is in the same units (usually °C or K) as the coefficient of linear expansion.