Thermal Physics
Temperature Changes
☆ When an object is heated, whilst in a constant state, the
temperature of the object will increase.
☆ This increase depends on the energy being transferred, the mass
of the substance being heated and a property of the material
known as the specific heat capacity.
☆ Specific heat capacity is defined as the energy required to raise
the temperature of 1kg of a given substance by 1 degree Kelvin.
☆ The equation linking these factors is:
∆E = mc∆θ
Changes of State
☆ For an object to change state, the particle arrangement of the
substance must be changed.
☆ For this to happen, there must be a transfer of energy in order
for bonds to be broken or created.
☆ The amount of energy required depends on the mass of the
substance as well as the specific latent heat of the given
substance.
☆ In general, specific latent heat is the energy required to change
the state of 1kg of a substance without a change in temperature.
☆ There are two forms of specific latent heat:
1. Specific latent heat of fusion is used for the transition
between solid and liquid,
2. Specific latent heat of vaporisation is used for the
transition between liquid and gas.
∆E = ml
Internal Energy
☆ The internal energy of a substance is defined as the sum of the
randomly distributed potential and kinetic energies of the
particles that make up the substance.
☆ When a substance undergoes a temperature change, the kinetic
energy of the particles increases, resulting in an increase in
the total internal energy of the substance.
☆ This is because temperature is a measure of the average kinetic
energy of the particles in the substance.
Temperature Changes
☆ When an object is heated, whilst in a constant state, the
temperature of the object will increase.
☆ This increase depends on the energy being transferred, the mass
of the substance being heated and a property of the material
known as the specific heat capacity.
☆ Specific heat capacity is defined as the energy required to raise
the temperature of 1kg of a given substance by 1 degree Kelvin.
☆ The equation linking these factors is:
∆E = mc∆θ
Changes of State
☆ For an object to change state, the particle arrangement of the
substance must be changed.
☆ For this to happen, there must be a transfer of energy in order
for bonds to be broken or created.
☆ The amount of energy required depends on the mass of the
substance as well as the specific latent heat of the given
substance.
☆ In general, specific latent heat is the energy required to change
the state of 1kg of a substance without a change in temperature.
☆ There are two forms of specific latent heat:
1. Specific latent heat of fusion is used for the transition
between solid and liquid,
2. Specific latent heat of vaporisation is used for the
transition between liquid and gas.
∆E = ml
Internal Energy
☆ The internal energy of a substance is defined as the sum of the
randomly distributed potential and kinetic energies of the
particles that make up the substance.
☆ When a substance undergoes a temperature change, the kinetic
energy of the particles increases, resulting in an increase in
the total internal energy of the substance.
☆ This is because temperature is a measure of the average kinetic
energy of the particles in the substance.
