Thermodynamics Flashcards
(27 cards)
What is heat?
Energy in transit due to temperature differences
How do you calculate Celsius to Fahrenheit?
9/5 celsius + 32
How do you calculate Celsius from Fahrenheit?
5/9 Fahrenheit -32
What does Fahrenheit divide the spread between freezing and boiling points?
180 degrees
What is absolute temperature measured in?
Kelvin and rankines
What is total temp the sum of?
Static temperature and temperature rise caused by ram effect.
What is the SI unit of heat energy?
Joule
What is calorie?
Heat required to raise the temperature of one gramme of water by one Celsius degree.
1 cal = 4.1868 joules
What is British thermal unit?
Energy required to raise the temperature of 1lb of water by 1 Fahrenheit degree.
1 BTU = 1055.06 joules
How many BTU is one therm?
100,000 BTU
What has the highest specific heat of any substance?
Water (except for hydrogen)
What’s the formula for changing a solid to a liquid with finding the thermal energy?
Thermal energy = latent heat x mass
What heat changes a solid to a liquid?
Latent heat
What is boyle’s law?
Relationship between pressure and volume of a gas.
Pressure exerted by a gas held at constant temp varies inversely with volume.
V1/V2 = P2/P1
What is Charles law?
Direct relationship between temperature and volume of gas.
Assuming no change in pressure, doubling of absolute temperature would double the volume of that gas.
V1/V2 = P1/P2
What is absolute humidity?
Actual water content of the air.
Mass/volume
What is relative humidity?
The amount of water in relation to how much water could be held.
Dew point. (Actual vapour/ possible vapour)
What is specific humidity?
Mass of water vapour in a unit of dry air.
Mass of water vapour/ mass of dry air + mass of water vapour.
What does a hygrometer measure?
Humidity.
One dry bulb and one moist bulb.
How can you work out work done?
Pressure x change in volume
What are the 3 ways of heat transmission ?
Conduction, convection and radiation
How does conduction heating work?
Heat transferred from one particle to another.
What is convection heating?
Liquids and gases.
Fluids flow from one place to another because of density difference causing unequal temps.
How does radiation occur?
Through electro magnetic waves
