Introduction:
In order to understand which metal bar's pins will start falling first, we need to consider the concept of heat conduction and how it affects different materials.

Heat Conduction:
Heat conduction refers to the transfer of heat energy between objects or substances that are in direct contact with each other. It occurs due to the movement of particles within the material. The rate of heat conduction depends on various factors, including the material's thermal conductivity and its specific heat capacity.

Factors Affecting Heat Conduction:
Several factors influence the conduction of heat in materials:

1. Thermal Conductivity: The thermal conductivity of a material determines how easily heat flows through it. Materials with higher thermal conductivity transfer heat more efficiently.

2. Specific Heat Capacity: Specific heat capacity refers to the amount of heat energy required to raise the temperature of a given mass of a substance by a certain amount. Materials with higher specific heat capacity require more heat energy to increase their temperature.

3. Temperature Gradient: The temperature difference between two points in a material is known as the temperature gradient. Heat conduction occurs from regions of higher temperature to regions of lower temperature.

Analysis:
To determine which metal bar's pins will start falling first, we need to consider the thermal conductivity and specific heat capacity of the metals involved. Generally, metals have high thermal conductivity, meaning they can conduct heat efficiently.

However, the specific heat capacity of the metals can vary. Specific heat capacity is the amount of heat energy required to raise the temperature of a given mass of a substance by a certain amount. Metals with higher specific heat capacity require more heat energy to increase their temperature.

Therefore, the metal bar with a higher specific heat capacity will take longer to heat up, resulting in a slower transfer of heat to its pins. On the other hand, the metal bar with a lower specific heat capacity will heat up more quickly and transfer heat to its pins faster, causing them to fall first.

Conclusion:
In conclusion, the metal bar with a lower specific heat capacity will likely start losing its pins first. This is because it will heat up more quickly and transfer heat to its pins at a faster rate compared to the metal bar with a higher specific heat capacity.

When the heat passes through a solid object..