Physics Chapter 12 Conceptual

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

81 times faster

conduction

Conduction transfers heat via direct molecular collision. An area of greater kinetic energy will transfer thermal energy to an area with lower kinetic energy. Higher-speed particles will collide with slower speed particles. The slower-speed particles will increase in kinetic energy as a result

H and O molecules in a sample gas have the same temperature, this means, on avg, the H molecules have the same

KE, but more speed

radiation

Thermal radiation generates from the emission of electromagnetic waves. These waves carry the energy away from the emitting object. Radiation occurs through a vacuum or any transparent medium (either solid or fluid). Thermal radiation is the direct result of random movements of atoms and molecules in matter

in the mountains, water boils at

a lower temperature than at sea level

by what primary heat transfer does one end of a metal spoon become 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, radiation, and evaporation

ice is put into a cooler in order to cool the contents. To speed up the cooling process, the ice can be

crushed

when water freezes, the entropy of the water

decreases

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

expands

a good reflector of radiation is a

poor absorber of radiation

a good head conductor is a

poor insulator

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

if you hold your hands to one side of the flame, the predominant form of heat transfer that you will experience is

radiation

the planet earth loses heat mainly by

radiation

the silver coating on the glass surface of a Thermos bottle reduces energy that is transferred by

radiation

an inventor discovers a harmless and tasteless salt, which, when added to water changes to its boiling point. The market value for this salt will be best if the salt

raises the boiling point of water

when liquids change to a solid phase, they

release energy

when a gas is changed to a liquid phase, the gas

releases energy

a refrigerator

removes thermal energy from inside the fridge

suppose you are served coffee at a restaurant before you are ready to drink it. In order for it to be the hottest when you are ready for it, you should add cream

right away

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

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 the refrigerator is produced by

vaporizing the refrigeration liquid

which one of the following statements best explains why metal pipes cary water often burst during the cold winter months

water expands upon freezing while the metal contracts a lower temperatures

by blowing on a cup of hot coffee

we remove water vapor above the coffee so that further evaporation is enhanced

suppose you walk on read hot coals with bare feet. Providing bits of coal do not stick to your feet, it would be best if you feet are

wet

which would burn the most

100 g of steam at 100 C

what is the theoretical efficiency of a Carnot engine that operates between 600 K and 300 K

50%

objects that radiate well

absorb radiation well

when a solid is changed to a liquid, the solid

absorbs energy

saturation occurs in air when the

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

cold water will warm to room temperature faster in a

black pot

hot water will cool to room temperature faster in a

black pot

if you want to cook eggs by boiling them while in the mountains, then compared to sea level, you should

boil the eggs for a longer time

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

cant say, thermal energy is not temperature

Which material is a good thermal insulator

concrete

consider steaming aluminum can that contains a small amount of boiling water. When it is quickly inverted into a bath of cooler water, the can is dramatically crushed by the atm pressure. The 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 water without ice on a warm day will warm up

faster

energy transfer by convection is primarily restricted to

fluids

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

gives up additional energy when it condenses AND has more energy per square kilogram than boiling water

a good absorber of radiation is a

good emitter of radiation

when a vapor condenses

heat energy leaves the substance

which heat is the greatest

heat necessary to vaporize 1 kg of boiling water

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

less than its surroundings

food in a pressure cooler is cooked faster because of the

higher temperature

your feet fell warmer on a rug than on a tile floor because a rug

is a better insulator than tile

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

less than at sea level

double up the absolute temperature of He gas, and the molecules of He speed up by

less than twice

metals are both good heat conductors and also good electrical conductors because

looseness of outer electrons in metal atoms

food cooked in boiling water in the mountains cooks slower than when cooked at sea level. If the temperature under the pot in increased, the food will cook

neither slower or faster

convection can occur

only in liquids and gases

a chunk of ice (20 C) is added to a thermally insulated container of cold water (O C). What happens in the container

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

sea breezes on a beach area attributed to a difference between land and water with respect to what property

specific heat

if a molecule 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 involves the larger number of calories

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

a water filled paper cup held in a flame will not catch fire because

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

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

transfer some of the KE to us

convection

When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. This type of heat transfer is called convection

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

convection

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

density and pressure

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

density increases

what happens to water when its temperature is reduced from 12 degree to 4

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