Table of Contents
What is the apparent expansion of a liquid? Explain.
When a liquid is heated in a container, the expansion of the liquid that is observed, i.e., the expansion of the liquid when the expansion of the container is not considered, is called the apparent expansion of the liquid. When a liquid is heated in a container, both the liquid and the container expand. The expansion of the liquid when the expansion of the container is considered is called the real expansion.
Real expansion = Apparent expansion + Expansion of the container
Apparent expansion = Real expansion – Expansion of the container.
How does the expansion of matter happen when heat is applied? Explain.
When a solid body is heated, the atoms in the body gain additional energy from the heat, increasing their kinetic energy. This increased kinetic energy causes the atoms to vibrate or move more vigorously. As a result, the intermolecular bonds between the atoms weaken, and they move further apart from each other, occupying more space than before. This process of expansion due to heat application is known as the expansion of solids. The amount of expansion varies depending on the material of the solid.
Why are gaps left between the rails of a railway track? Explain.
Railway tracks are made of iron plates. Due to the heat of the sun or the friction generated by the wheels of a moving train, the iron plates, or the railway track, expand. This expansion can cause the railway track to bend, leading to accidents. Therefore, gaps are left between the two connecting plates of the railway are left between the two connecting plates of the railway track to provide sufficient space for the track to expand.
What is the expansion of area? Explain.
When the temperature of a solid object increases, its area increases along with its length. This is called expansion of area. Each solid material has a specific areal expansion coefficient. Therefore, with the same amount of heat applied, the increase in area of materials with different areal expansion coefficients will be different.
What is volume expansion? Explain.
When the temperature of a solid object increases, its volume increases. This is called volume expansion. Each solid material has a specific volume expansion coefficient. Therefore, with the same amount of heat applied, the increase in volume of materials with different volume expansion coefficients will be different.
How a person’s body temperature is measured using a mercury thermometer? Explain.
A mercury thermometer can be used to measure a person’s body temperature by observing the rise and fall of mercury in a narrow glass tube due to changes in temperature. The heat from the person’s body causes the mercury to expand and rise to a specific height. The temperature can be measured by reading the value marked at this height.
