2.3 Thermodynamics Flashcards
What is temperature?
Measure of average kinetic energy of the particles in a system.
How is thermal equilibrium reached?
When heat flows from a hotter to cooler body and stops when they are the same temp.
What is the difference between heat and temperature?
Temperature is the property of a body and heat is the energy that flows too or from a body.
What are the three types of thermometers?
Bulb
Bimetallic
Thermistor
What is a thermocouple?
They are used to measure high temp, used for applications in the engine.
What is a bulb thermometer?
The classic type you find everywhere.
What is a bimetallic thermometer?
It shows temp as mechanical displacement. They can be used as a heat switch.
What is a thermistor?
A device to measure temp, the electrical resistance changes with temp.
How do you convert Fahrenheit to celsius?
F-30/2
How do you convert Celsius to Fahrenheit?
C x 1.8 + 32
Which measure of temp is the SI units?
Kelvin.
What is absolute zero in degrees celsius?
-273.15
What is the key difference between Calorie and calorie?
The lower case calorie is 1/1000th of a Calorie.
How does heat flow from a lower to higher object?
If work is done.
What is specific heat?
The energy required to raise the temp of 1kg object by 1 degree c.
What is the formula for specific heat?
Heat energy added divided by mass x change in temp
How do you work out the heat given to an object to heat its mass?
mass x specific heat x temp change
What is heat capacity?
Ratio of the amount of heat energy transferred to an object to the change in temp.
What are the three methods of heat transfer?
Convection, conduction and radiation.
What is conduction?
Heat is directly transferred through the material. Only method of heat transfer in solids, sometimes in liquids.
What is convection?
Heat transfer in liquids and gasses.
What is radiation?
Energy coming from source and travelling through space. It is different to conduction and convection in that the objects do not need to be in contact.
What is the coefficient of linear thermal expansion?
The amount that different materials expand/contract when heated or cooled.
What is linear expansion?
The change in length proportional to the original length and change in temp.