Physics Chapter 7

if you triple the absolute temperature of an object, it will radiate energy

81 times faster

in the mountains, water boils at

a lower temperature than at seal level

what primary heat transfer mechanism does on end of a metal spoon becomes hot when the other end is placed in boiling water

conduction

the space between the inner walls of a thermos bottle is evacuated to minimize heat transfer by

conduction and convection

a substance can absorb heat energy by the process of

conduction convection and radiation

if air were a better conductor than it is, at nighttime the earth would be

considerably colder

if your hands are being warmed by holding them above a flame, then the primary form of heat transfer is which process

convection

when a volume of air is compressed, its temperature

decreases

when water freezes, the entropy of the water

decreases

warm air rises because faster moving molecules tend to move to regions of less

density and pressure

what happenes to water when its temp is reduce from 12 to 4 celsius

density increases

what happens to water when heated from 0 degrees to 4 celsius

density increases

the second law of thermodynamics leads us to conclude that

disorder in the universe is increasing with the passage of time

if a volume of air is warmed, it

expands

what happens to a given mass of water when cooled between 4 and 0 celsius

expands

a good reflector of radiation is a

poor absorber of radiation

increased air pressure on the surface of hot water tends to

prevent boiling

by what primary heat transfer mechanism does the sun warm the earth

radiation

if holding hands to one side of a flame,the predominant form of heat transfer is what process?

radiation

the planet earth loses heat mainly by

radiation

the silver coating on the glass surfaces of a thermos bottle reduces energy that is transferred

radiation

the primary reason why a sandy beach gets so hot on a sunny day is because

sand has a small specific heat

evaporation is a cooling process because

the more energetic molecules are able to escape the liquid

is it possible to transfer heat from a cold reservoir to a hot reservoir

yes but work will have to be done

the cooling effect inside a refrigerator is produced by

vaporizing the refrigeration liquid

objects that radiate relatively well

absorb radiation relatively well

saturation occurs in air when the

air contains as many water molecules as it can contain in a given temperature

if you were caught in freezing weather with only a candle for heat, you would be warmer in

an igloo

cold water will warm to room temperature faster in a

black pot

hot water will cool to room temperature faster in a

black pot

an object will normally be a net radiator of energy when its thermal energy is

can't say

which material is a good thermal insulator

concrete

consider a steaming aluminum soda pop can that contains a small amount of boiling water. when it is quickly invented into a bath of cooler water, the can is dramatically crushed by atmospheric pressure. this occurs because the pressure inside the can is rapidly reduced by

condensation of steam inside

compared to a glass of ice water with ice in it, a glass of plain ice-cold water without ice on a warm day will warm up

faster

energy transfer by convection is primarily restricted to

fluids

steam burns re more damaging than burns caused by boiling water because steam

gives up additional energy when it condenses and has more energy per kg than boiling water

a good absorber of radiation is a

good emitter of radiation

a good heat conductor is a

good insulator

when a vapor condenses

heat energy leaves the substance

which heat is the greatest

heat necessary to vaporize 1kg of boiling water

food in a pressure cooker is cooked faster because of the

higher temperature

your feet feel warmer on a rug than on a tile floor because the rug

is a better insulator than tile

hydrogen and oxygen molecules in a sample gas have the same temperature. this means the hydrogen molecules, on average, have the same

kinetic energy, but more speed

when bringing water to a boil in the mountains, the time needed to reach boiling point is

less than at sea level

if a poor absorber of radiation were a good emitter, its temperature would be

less than its surroundings

double the absolute temperature of helium gas, the molecules of helium speed up by

less than twice

metals are both good heat conductors and also good electrical conductors bc of the

looseness of outer electrons in metal atoms

convection can occur

only in liquids and gases

a chunk of ice is added to a thermally insulated container of cold water. what happens in the container

some of the water freezes and the chunk of ice gets larger

if molecules in a sample gas moved so they completely missed each other, the gas's temperature would

stay the same

when heat is added to boiling water, the water temperature

stays the same

which involved the larger number of calories

the condensation of 1g of steam at 100 celsius to 100 celsius water

a water-filled paper cup held in a flame will not catch fire. this is because

the paper cup cannot become appreciately hotter than the water it contains

we are warmed by condensation because water molecules in the air that strike our bodies

transfer some of their kinetic energies to us