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