Question

Many objects, such as train tracks and road joints, are specifically designed to allow extra space for _______ ​

Answer 1

All metals expand when heated. The expansion of each metal is a function of its thermal properties and vary from metal to metal. When laying down railway tracks, sufficient spacing is allowed between two successive rails to allow for expansion of tracks during summer months. This spacing causes slight discomfort during the travel, since the train motion is not very smooth and this also causes noise. Yet, this spacing between joints is necessary to allow for expansion and contraction of the track material. Imagine what will happen, if there were no spacing between successive tracks. During the warm months, when the temperature is high, the track material will expand due to heat and the tracks will push against each other. During the night time, the tracks will contract and pull away from each other. The constant tug between the tracks will cause very high wear and tear and make the train motion unsafe.

Hope this helps.

Answer 2

Answer:

Many objects, such as train tracks and road joints, are specifically designed to allow extra space for thermal expansion.

Explanation:

• During summers there is an increase in the temperature.
• Road joints, train tracks etc, are made up of metals.
• Metals have the tendency to expand when heat is applied.
• This phenomenon is termed as thermal expansion.
• The extent of thermal expansion varies from material to material.