Ch14 Thermal physics Flashcards
DEFINITION OF TEMPERATURE
Measure the average kinetic energy of the particles in a substance.
DEFINITION OF HEAT
Describe the transfer of thermal energy from a region of high temperature to a region of low temperature.
TEMPERATURE IN KELVIN
T(K) = T(C) + 273
ABSOLUTE ZERO
The lowest temperature, where particles in a substance have minimal kinetic energy.
BROWNIAN MOTION
refers to the random, erratic movement of particles suspended in a fluid (liquid or gas) as a result of collisions with the much smaller, fast-moving molecules of the surrounding fluid.
SPECIFIC HEAT CAPACITY
The amount of energy required to raise the temperature of 1KG by 1•K
Thermal equilibrium
energy transfer from region of high temperature to a region of low temperature
Solid
the particles vibrate in a fixed ordered.
if the temperature increase the amplitude of vibration increases
liquid
the particles can flow past each other. they are vibrating but not in a fixed position.
Gas
particles are far apart. they dont exert forces on each other except in collisions, they move in random linear motion
Internal energy
the sum of kinetic and potential energies of all the particles of a substance
specific latent heat
the energy required to change the state of a substance without any change in temperature
types of specific latent heat
Latent heat of fusion: energy required to melt substance without change in temperature
latent heat of vaporisation: energy required to vaporise a substance without change in temperature
Brownian motion Observation and explanation.
observation: smoke particles are moving in a random linear motion.
explanation: as they are colliding with air particles that are also moving in random linear motion.
observation: air particles cannot be seen.
explanation: as they are smaller than the smoke particles.
SHC EXPERIMENT.
equipments:
- power supply
- variable resistor
- ammeter
- voltmeter
- immersion heater
- thermometer
- insulated container
SHC EXPERIMENT.
measurements:
- measure the mass of the liquid
- measure the current using the ammeter
- measure the voltage using the voltmeter
- measure the temperature at set time intervals
- measure the time interval using a clock watch
SHC EXPERIMENT.
to reduce uncertainty:
- stir the liquid regularly as the temperature of the liquid will be uneven
SHC EXPERIMENT.
finding SHC:
- plot a graph of temperature against time.
rearrange E=mc c temperature to get p = mc x temperature/ time
temperature/time is the gradient
rearrange c to be the subject
LH EXPERIMENT.
equipments:
- power supply
- ammeter
- voltmeter
- variable resistor
- immersion heater
- ice
- beaker
LH EXPERIMENT.
measurements:
- measure current
- measure voltage
- measure mass of melted ice
- measure time taken
LH EXPERIMENT.
finding LH:
use
E=mL
VI=mL
rearrange for L
