Thermal Physics Flashcards
What is internal energy?
The sum of randomly distributed kinetic energies and potential energies of particles in a body.
For example in a glass of water the kinetic is is the energy associated with movement, and the potential energy is associated with any forces or interactions between the particles, such as electrostatic attraction or repulsion.
What factors affect the kinetic and potential energy of particles?
Kinetic - temperature
Potential - intermolecular forces
What is a fluid
a substance that can flow
What is the first law of thermodynamics?
The increase in internal energies of a system = the thermal energy added to the system - the work done by the system
When a gas expands, what happens and why.
The The gas does work on the surroundings. The force = pressure * piston area
The work done on the piston also = Forces * distance
substitute F = pA you get
change in work = pressure * change in volume
What happens when substances are heated?
- Thermal energy is supplied to the particles
- increasing internal energy U
- increasing average kinetic energy
Thermal energy = mass * specific heat capacity * change in temperature(kelvin)
What is specific heat capacity?
- A fundamental property of a material
- The amount of thermal energy required to raise the temperature of 1 kg of a substance by 1 °C (or 1 K) without a change of state
What is specific latent heat?
The amount of thermal energy required to change the state of 1kg of a material, without a change in temperature, at a specified ambient pressure.
What is the amount of energy required to change the state of a substance.
mass * specific latent heat
What is Boyle’s Law?
for a fixed mass of an ideal gas at a constant temperature,
pressure is inversely proportional to volume.
p1V1 = p2V2
What is Amonton’s law?
The pressure of a fixed mass and fixed volume of a gas is directly proportional to the absolute temperature of the gas.
p1/T1 = p2/T2
What is Charles Law?
At constant pressure, the volume of a fixed mass of an ideal gas is directly proportional to its absolute temperature.
v1/T1 = v2/T2
What is absolute zero?
The temperature when all molecular motion ceases, and the pressure of a gas drops to zero.
0 Kelvin or -273.15°C
What is standard room temperature and pressure?
0 degrees Celsius and 1.01 *10^5 Pa (1 atm)
What is room temperature and pressure?
25 degrees Celsius and 1 atm
