6.2 Thermal physics Flashcards
What is the basic rule in Thermal Physics regarding heat transfer?
Heat energy will transfer from a hotter object to a cooler object.
What defines a ‘system’ in Thermal Physics?
A ‘system’ consists of objects where heat can only transfer between them, with no heat lost or gained from their surroundings.
What happens when two blocks are not considered a ‘system’?
They may transfer heat to or from their surroundings, even if they are close together.
What mechanism allows heat energy to transfer between objects in a system?
Heat conduction.
What is required for objects to obey the 1st Law of Thermodynamics?
They must be super-insulated from their surroundings.
What does the 1st Law of Thermodynamics state?
The internal energy of a system changes when energy is transferred to it by heating or when work is done on it.
In the example of two blocks, what happens to the temperature of block A and block B during heat transfer?
Block A cools down and block B warms up until they reach thermal equilibrium.
What is thermal equilibrium?
A state where there is no net heat transfer between objects.
What is the relationship between the internal energy lost by object A and the internal energy gained by object B?
The total internal energy lost by object A is equal to the total internal energy gained by object B.
Fill in the blank: Heat energy will transfer from a _______ object to a cooler object.
[hotter]
What happens to the kinetic energy of atoms in a hot block when in contact with a cool block?
Atoms in the hot block lose kinetic energy
This transfer continues until thermal equilibrium is reached.
What happens to the kinetic energy of atoms in a cool block when in contact with a hot block?
Atoms in the cool block gain kinetic energy
This transfer continues until thermal equilibrium is reached.
What is thermal equilibrium?
No further net heat energy transfer occurs
It is the state where objects reach the same temperature.
How is temperature related to kinetic energy?
Temperature is related to the average kinetic energy of the particles
Objects at the same temperature will have particles with the same average kinetic energy.
True or False: In reality, every particle in the same object has exactly the same kinetic energy.
False
Some particles may have different kinetic energies.
What occurs when a hot cooking pan is placed into cooler water?
The pan cools down and the water heats up
They will both reach the same final temperature.
Fill in the blank: The heat energy lost by the drink when putting ice cubes in it is transferred in ______ stages.
3 stages
Each stage involves different processes of heat transfer.
What is the first stage of heat transfer when ice cubes are added to a drink?
The ice warms up from its initial temperature to its melting point
This stage prepares the ice for melting.
What happens in the second stage of heat transfer when ice cubes are added to a drink?
The ice melts to become water at 0°C
This stage involves a change of state for the ice.
What occurs in the third stage of heat transfer after ice has melted?
The water at 0°C warms up to the new equilibrium temperature
This is the final temperature that the drink cools down to.
What is a key consideration in heat transfer problems?
Think through the stages of any heat transfer occurring
This helps in understanding the entire process.
