Theme B Flashcards
Define thermal equilibrium
When there is no net heat flow between two objects.
State the zeroth law of thermodynamics
If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other
Define temperature
The quantity which is equal between two objects in thermal equilibrium, such that heat spontaneously flows from high to low temperature.
Define internal energy
The sum of the total kinetic energy of the particles in a system and the total potential energy due to intermolecular forces, between the particles in the system.
What is heat according to kinetic theory
The transfer of internal energy between systems due to difference in tempuratures
What is temperature according to kinetic theory
A measurement of average internal kinetic energy of a system
Define conduction
Heat transfer through the contact forces
Define convection
Heat transfer via fluid between objects
Radiation
Heat transfer via electromagnetic radiation
State the formula relating thermal conductivity and heat:
Where:
∆Q = heat (J)
∆t = duration
k = thermal conductivity
A = cross-sectional area
∆T = different in temperature between the ends of the solid
∆x = width
Define heat capacity
The heat required to increase the temperature of a system by one unit
State the formula for specific heat capacity
Where:
Q = heat
m = mass
c = specific heat capacity
∆T = change in temperature
Define latent heat
Heat which doesn’t result in a temperature change as it is resulting in a phase change.
State the formula for specific latent heat.
Where:
Q = heat
m = mass
L = specific latent heat
Define pressure
Perpendicular force per unit area over the surface of the system.
State the formula for pressure
Where:
P = pressure
F = force
A = area
Base SI units for pressure
Pascal, Pa
Pa = N⋅m⁻²
What is the unified atomic mass unit
One twelfth of the mass of a carbon-12 atom