Conceptual Physics-Heat and Density Flashcards
Conduction
Heat transfer by direct contact of molecules
Convection
Heat transfer by movement of groups of particles (hotter molecules rise, colder molecules sink)
only in gases and liquid
caused by differences in density
Mass
amount of matter in an object
Volume
how much space something takes up/occupies
Density
Mass/Volume
matter per unit of space
grams/cubic centimeter or milliliter
g/cm3 or g/mL
Radiation (not nuclear…)
heat transfer by electromagnetic (EM) waves
can occur anywhere, even vacuums like space
blank things absorb heat
black or dull
blank things reflect heat
white or shiny
Thermodynamics
study of heat energy
Thermal equilibrium
when two or more solids, liquids, and/or gases of differing temperatures are placed near each other, they gradually will become the same temperature.
R Value
Stands for resistance to heat flow
higher= better insulation
To find total of combined R values, add
In boiling water, heat is transferred by groups of molecules that rise as they become less dense. This is an example of blank
convection
You touch a hot panhandle and you are burned. This is an example of blank
conduction
A radiator near the floor heats up the air around it. This air rises towards the ceiling, where it gradually cools and sinks to the floor, where it is heated again. This is an example of blank
convection
The sun heats the earth. This is an example of blank.
radiation
You pick up an icecube and hold it in your palm. It begins to melt (not because of heat from a source other than your hand). This is an example of blank.
conduction
A fire heats up a room. This is an example of blank.
Radiation
What heat transfer can occur in a vacuum?
radiation
Insulation prevents heat loss by:
?
Heat is transferred into a house
?
Heat always moves from blank1 to blank2.
hot to cold
Does heat rise?
No. Hot gases or liquids rise because they are less dense. Heat moves in whatever direction the colder substance is.
Insulators
slow down heat transfer
air pockets are good insulators
Conductors
easily allow heat transfer
most metals are good conductors
solids have blank1 density and are better blank2
high
conductors
gases have blank1 density and are better blank2
low
insulators
Wind is created
when the sun warms air near the surface of ear, which rises. cooler air is pulled in beneath it to take its place, creating wind
radiation transfers heat in which directions?
all
Radiation blank transparent materials
goes through
When hot air rises; causes wind; within a pan of boiling water- these are examples of blank
convection
when two objects are touching; when atoms collide; between a stove and a pot; though a car’s windows at night- these are examples of blank
conduction
when nothing is touching; transfers heat in all directions; more occurs with dark objects- these are examples of blank
radiation
name good insulators
wood; air; coat; styrofoam
name good conductors
metal; glass; copper; water; aluminum
Name things that absorb heat or heat fast
dark liquids; dull objects; black paper; dark car
Name things that reflect heat or heat slowly
clear liquids; shiny objects; white paper; aluminum; styrofoam
Bonus! Name the three systems to measure heat and mention which need a degree symbol.
DEGREES Celsius
DEGREES Fahrenheit
Kelvins (no degrees!!!)
