Thermal expansion and contraction：練習問題

According to the particle theory, why does a substance expand when it is heated?

If equal volumes of a solid, a liquid, and a gas are all heated by the same increase in temperature (e.g., from \( 20^\circ\text{C} \) to \( 80^\circ\text{C} \)), which state of matter will generally show the greatest amount of expansion?

Consider two bimetallic strips:
Strip 1: Aluminum and Steel
Strip 2: Copper and Steel
Given that the expansion rate of Aluminum > Copper > Steel, which strip will show greater curvature (bend more) when both are heated from \( 20^\circ\text{C} \) to \( 80^\circ\text{C} \)?

When most solid materials are heated, their physical dimensions change. What is the general term for the increase in the volume of a solid when its temperature rises?

A metal lid on a glass jar is stuck and cannot be opened. After pouring hot water over the metal lid for a minute, it becomes easier to unscrew. Why does this happen?

Using the particle theory, explain what happens to the average distance between particles in a solid when its temperature increases.

When a student observes a bimetallic strip made of brass and iron, they notice that the strip is straight at room temperature. Brass is known to have a higher rate of thermal expansion and contraction than iron. If the strip is placed in a container of liquid nitrogen (which is extremely cold), in which direction will the strip bend and why?

A metal washer (a flat disk with a central hole) is heated uniformly from \( 20^\circ\text{C} \) to \( 200^\circ\text{C} \). Using the particle theory, explain why the diameter of the central hole increases rather than decreases as the metal expands.

A metal lid is tightly stuck on a glass jar. To open it, a student pours hot water over the metal lid for a few seconds.

(a) Describe the change in the volume of the metal lid when it is heated by the hot water. (1 point)

(b) Metals generally expand more than glass for the same increase in temperature. Explain how this difference helps the student unscrew the lid. (1 point)

(c) Using the particle theory, describe how the motion of the particles in the metal lid changes as their temperature increases. (1 point)

(d) Suggest one other example of thermal expansion that can be observed in daily life. (1 point)

(a) Explain how a liquid-in-glass thermometer works to measure temperature, making reference to the thermal expansion of the liquid and the particle theory.
(b) Would a gas thermometer (if it existed in this simple form) be more or less sensitive than a liquid-in-glass thermometer to temperature changes? Explain your answer in terms of the arrangement and movement of particles in gases compared to liquids.