Thermodynamics Flashcards
What is temperature?
A measurement of the average kinetic energy of the particles in a system
When an object warms up what happens to the particles?
They move faster
What happens if you had two objects at different temperature?
Heat will flow to the colder until their temperatures are identical and thermal equilibrium is reached
What is a thermometer?
A temperature measuring instrument
What are the three main types of thermometers?
-bulb thermometer
-bimetallic thermometer
-thermistor
What are thermocouples used for?
Measurement of high temperature
Why is mercury used in thermometers?
They have a linear rate of expansion with rising temperature
In a bulb thermometer what happens when temperature rises?
The fluid expands and moves up the tube
Why is water not used in thermometers?
Because it would freeze or boil
How does a bimetallic thermometer work?
Two different metals are bonded together and when the temperatures rises or falls the bonded metal will bend in a certain direction
A thermistor is a combination of two words, what are these words?
Thermal and resistor
How does a thermistor work?
A wire that changes its electrical resistance with change in temperature
What is the most commonly used sensor to measure temperature?
A thermistor
What temperature range is used in the metric system?
Celsius or centigrade
Where is Fahrenheit used?
USA and some Caribbean countries
In Fahrenheit what is the freezing point of water?
32˚F
In Fahrenheit what is the boiling point of water?
212˚F
What is the only temperature that is the same in Celsius and Fahrenheit?
-40˚
When is kelvin used as the base unit for temperature?
In the SI units
What is the lowest possible temperature?
Absolute zero
What would happen to ordinary gases like air if they reached absolute zero?
They’d become rock solid
Is it possible to get to absolute zero?
No but we can get to a fraction of ˚C from it
What is the equation to work out kelvin?
K = C + 273.15
What is heat?
A measurement of energy transferred from one substance to another