ch. 17 physics
Steam burns are more damaging than burns caused by boiling water because steam
) has more energy per gram than boiling water. B) releases additional energy when it condenses. C) both of these
The minimum amount of steam at 100°C needed to melt 1 gram of 0°C ice is
0.125g
Which will melt more ice when placed on its surface, a kilogram of wood or a kilogram of iron of the same high temperature?
1 kg of wood
To increase the temperature of 50 grams of water by 2 Celsius degrees requires
100 calories
A boy scout will be burned more severely by
100 g of steam at 100°C
The calories needed to change 10 grams of ice at 0°C to steam at 100°C is
7200
The mass of ice that can be melted by 1 gram of 100°C steam is (Hint: Don't forget about hot water remaining from condensed steam.)
8 g
The toy drinking bird nicely illustrates
A) evaporation. B) condensation
In a heat pump, warming is accomplished when
Condensation occurs in its coils
When water freezes, the surrounding air is
Warmed
The molecules in a room-temperature glass of water jostle around at
a great variety of speeds
Compared to sea level, water in an open pot in the mountains boils at
a lower temperature
Evaporation is a cooling process and condensation is
a warming process
When a solid melts, energy is
absorbed by the solid
When vapor transforms to a plasma, energy must be
absorbed by the vapor
When a solid is changed to a liquid, the solid
absorbs energy
The main difference between a fog and a cloud is
altitude
Water can be brought to a boil by
applying heat and reducing air pressure on its surface
A heat pump can
both of these
Ice is put in a cooler to cool the contents. To speed up the cooling process, the ice can be
broken into smaller pieces
A geyser such as Old Faithful in Yellowstone Park is similar to a
coffee percolator
When condensation occurs inside your bedroom window, the air outside is appreciably
colder
Double-pane windows contain nitrogen rather than air to prevent
condensation
We feel uncomfortably warm on a muggy day because water molecules are
condensing on our bodies
When you blow over hot soup to cool it you are helping
conduction, convection, and radiation
Melting snow tends to
cool the surrounding air
A canteen that is wet on the outside results in water inside that is
cooler
When a geyser erupts, pressure at its bottom
decreases
To melt ice, add
energy
The surface of hot water has a relatively high rate of
evaporation
Wrapping a hot potato in aluminum foil significantly reduces the rate at which it cools by
evaporation
What occurs in a pan of water placed outdoors on a warm day?
evaporation, condensation
Compared with sea-level cooking, in cooking eggs by boiling in mountain regions you should boil the eggs
for a longer time
Rapid evaporation of hot water can lead to
formation of ice
The addition of salt to water affects its
freezing point
Hydrothermal vents deep beneath the ocean surface attain temperatures far above 100°C due to
greater pressure
The pressure at the bottom of a geyser is
greater than nearer the top
Food in a pressure cooker is cooked faster due to
higher temperature
The temperature at which water freezes is the same as the temperature at which
ice melts
You can add heat without raising temperature to
ice. B) boiling water
Stored potatoes, beets, and rutabagas in an unheated well-insulated room can be protected from freezing by having in the room
large tubs of water
Foreign ions introduced to water
lower the freezing point of water
Water can be turned to ice by
lowering the surrounding air pressure. B) extracting energy
To turn 1 gram of boiling water to steam requires
more energy than needed to turn 1 gram of absolute-zero ice to the boiling point
To turn 50 grams of boiling water to steam requires
more than 540 calories
In mountain regions, food cooked in boiling water cooks slower than when cooked at sea level. If the temperature beneath the pot of boiling water is increased, the food will cook
neither
When you walk barefoot on red-hot wooden coals it is best if
no pieces of metal are among the coals
To melt 50 grams of 0-degree-Celsius ice requires
none of the above
Dean teaches that the phenomenon of regelation is due to the
open-structured nature of ice crystals
In one word, how can water in the power plant of a nuclear submarine far exceed 100°C?
pressure
Increased air pressure on the surface of hot water tends to
prevent boiling
An inventor discovers a harmless and tasteless salt, which when added to water changes its boiling point. The market value for this salt will be better if the salt
raises the boiling point of water
When fast-moving water molecules collide they tend to
rebound without sticking
Water in a car radiator sometimes boils explosively when the radiator cap is removed, which is due to sudden
reduced pressure
When liquids change to a solids, they
release energy
When moth balls sublime to gas they
release energy
When a vapor condenses, energy is
released from the vapor
When a gas is changed to a liquid, the gas
releases energy
When heat is added to boiling water, its temperature
remains unchanged
For increased atmospheric pressure, the boiling point of water
rises
Morning dew on the grass is a result of
slow-moving water molecules sticking to one another.
Firefighters find that the temperature of burning material is best lowered when water
sprayed as a fine mist
When slow-moving water molecules collide they tend to
stick
The most responsible factor for whether a substance takes the phase of solid, liquid, gas, or plasma is its
temperature
Which involves a larger number of calories?
the condensation of 1 gram of steam at 100°C to water at 100°C
The reason that evaporation is a cooling process is
the more energetic molecules escape the liquid
A good cook knows that the temperature of violently boiling water is
the same as that of simmering water
The temperature at which a liquid freezes is
the same temperature at which its solid form melts
Stored potatoes, beets, and rutabagas freeze at temperatures below zero degrees Celsius (rather than at exactly zero) because
the water in them contains dissolved salts and sugars
A hot dog pants
to enable evaporation in its mouth and bronchial tract
On a muggy day, water molecules in the air that strike our bodies
transfer some of their kinetic energy to us
A refrigerator
transfers internal energy from inside to outside
In a heat pump, cooling is accomplished when
vaporization occurs in its coils
The cooling effect inside a refrigerator is produced by
vaporizing the refrigeration liquid
During snow fall, the surrounding air is
warmed
When steam condenses, the surrounding air is
warmed
When water vapor changes phase to become water in a cloud, the surroundings become
warmer
When water vapor condenses on the inside of a window, the room becomes slightly
warmer
When ice crystals form in clouds, the surrounding air
warms
If bits of the coals do not stick to your feet while walking barefoot on red-hot coals, it would be best if your feet are
wet
To illustrate regelation with ice it is important that a
wire is used
As a block of ice at 0°C melts, the block absorbs energy
without a temperature change
