PHYSICS - PROPERTIES OF MATTER - Specific heat capacity

Temperature

measure of the average kinetic energy of the particles in a substance

degrees celsius ⁰C or Kelvin K

scalar

Heat

a form of energy transferred between objects due to temperature difference

joules J

scalar

specific heat capacity (c

amount of heat energy required to raise the temperature of 1kg of a substance by 1⁰C

J/kg⁰C

specific heat capacity formula

E =m x c x T

T = change in temperature

m = mass

amount if energy required depends on:

mass of substance

specific heat capacity of substance

temperature change

practical applications of SHC

water has a high SHC making it ideal for

regulating temperature in heating systems

used as a coolant in industries

materials with low SHC heat up and cool down fast

metals - used for cooking utensils and electrical components

concrete - used to retain heat and release it over time in storage heaters

Heat transfer mechanisms

conduction

convection

radiation

conduction

transfer of heat through solids via particle collisions

convection

transfer of heat in fluids due to differences in density

radiation

transfer of heat through electromagnetic waves

changes in state

during a change in state:

temperature remains constant even though heat energy is being absorbed or released

heat energy is used to break or form bonds between particles

high vs low SHC

High SHC = more energy to change temperature

Low SHC = heat up and cool down faster

Energy conservation and heat loss

some energy is lost to surroundings due to:

poor insulation

heat transfer to container and environment

improving accuracy in experiments

using insulators to minimise heat loss

stir substance to ensure even heat distribution

use lid to reduce heat loss to surroundings

use precise measuring instruments (digital thermometers and calibrated joulemeters)

Heat energy

form of energy transferred from one object to another due to temperature difference

flows from hot objects to cold objects until thermal equilibrium is reached

conservation of energy

energy cannot be created or destroyed

can be transferred from one object to another or from one form to another

total energy in a closed system remains constant

kinetic energy

energy due to motion

E = ½ mv²

m = mass in kg

v = velocity in m/s

thermal energy

energy caused by the movement if particles in a substance

E = mcT

potential energy

energy due to position in a field, such as gravitational potential energy

E = mgh

g = gravitational field strength (9.8N/kg Earth)

h = height in m

Energy transfer in heating

more heat energy, energy transferred to particles, increasing kinetic energy, rise in temperature

heat energy lose,energy transferred to surroundings or converted into another form