Physics Unit 8 Study Guide

the reason you can hold your fingers beside a candle flame without getting hurt is that ____________

1. air convects heat well 2. hot air rises 3. air is a poor heat conductor 4. hot air convection currents travel upward

clouds form when warm air________

1. expands 2. rises 3. chills

the reason sea breezes are usually from the sea toward the land during the day is that ______________

1. land is hotter than water 2. cool air high over the ocean flows downward 3. a high pressure area is created high above the water 4. a low pressure area is created just over the shore

the molecules in a room-temperature glass of water jostle around at

a great variety of speeds

evaporation is a cooling process and condensation is _____________

a warming process

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

an igloo

food cooked in boiling water in the mountains cooks more slowly than cooked at sea level. if the temperature under the pot is increased, the food will cook ____________________

at the same rate as before

if your take a shower in a steamy bathroom and then go to your bedroom to dry off, why will you feel colder in your bedroom?

because water evaporates off of your skin, your skin will be cooled

if you want to cook boiled eggs while in the mountains, you should ____________________

boil the eggs for a longer time

when snow forms, the air becomes warmer because ________________

changing from a vapor to a solid is a process that gives off energy

melting snow ________________

cools the surrounding air

ice is put in a cooler to cool the food stored there, in order to speed up the cooling process, you should ________________

crush the ice

heat transfer by conduction in metals occur when _________________

electrons bump into atoms and other electrons

a liquid is cooled if _________________________

evaporation exceeds condensation

condensation occurs when matter changes from a ________

gas to a liquid

when water freezes, it _______________

gives off energy

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

has a higher temperature than boiling water

as atmospheric pressure increases, the boiling temperature of a liquid ____________

increases

plastic foam is a good heat____________

insulator

a cup of hot coffee will cool faster if it ________

is black

at high altitudes, the boiling point of water _______________

is lower

a liquid boils when _________

it turns to vapor at the bottom of or in the liquid

heat transfer by convection occurs when _____________

large numbers of atoms move from place to place

when boiling water in the mountains, the time needed to reach the boiling is ________________

less than at sea level

evaporation takes places when matter changes from a __________

liquid to a gas

freezing occurs when matter changes from a ____________

liquid to a solid

energy transfer by convection is primarily restricted to ______________

liquids

a piece of metal will feel colder than a piece of wood at the same temperature. why?

metals, in general, are good heat conductors

heat travels from the sun to earth by ____________________

radiation

the reason pressure cookers cook food faster is that they _______________

raise the cooking temperature of the food

the reason light colored clothes help keeps you cool in warm weather is that clothes of light color ___________________

reflect a lot of energy

when water vapor condenses on the inside of a window, the window becomes ___________

slightly warmer

morning dew on the grass is a result of __________________

slow-moving molecules condensing on the grass

when heat is added to boiling water, the temperature of the boiling water ____________

stays the same

two pots are filled with boiling water. the pots are exactly the same size, but one pot is white and the other is black. which pots cools faster?

the black pot

to say that evaporation is a cooling process means that when evaporation occur,

the remaining liquid cools

on a humid day, water condenses on the outside of a glass of ice water. this phenomenon occurs mainly because of ___________________

the saturation of cooled air

to make freeze-dried coffee, you would spray drops of coffee into a vacuum chamber so that ___________

the water would boil off, which would cool the coffee until it freezes. once it freezes any remaining water molecules would evaporate

pigs roll in the mud _____________

to keep their skin wet so evaporation can occur

the cooling effect inside a refrigerator is produced by _________________________

vaporizing the refrigeration liquid

at night, a sea breeze results when __________________________

warm air over the ocean rises and cooler air from the shore takes its place

if a volume of air is warmed, it expands. if a volume of air expands it _________

warms

when snow forms in clouds, the surrounding air ___________

warms

in order to walk barefoot on hot coals without harming your feet, less energy would get to your feet if your feet were ___________________

wet

which will melt a bigger hole in a block of ice- a red-hot nail tossed on it or a red-hot piece of wood of the same mass and temperature ______________

wood