Exam 3
thermal conduction mainly involves...
electrons
When most substances are heated, molecules inside move faster and take up more space, resulting in thermal
expansion
compared with radiation from the sun, the terrestrial radiation has a lower...
frequency
Compared to a giant iceberg, a hot cup of coffee has
higher temperature, but less internal energy.
The color of heat is _____
infrared
Pour two liters of water at 40°C into one liter of water at 20°C and the final temperature of the two becomes
more than 30°C.
Translational motion is characterized by
motion that carries a molecule from one place to another
Heat energy travels from an object with a high
temperature to an object with a lower temperature
Temperature is generally proportional to a substance's
average translational kinetic energy
temperature is generally proportional to a substance's...
average translational kinetic energy
Consider a metal ring with a gap cut in it. When the ring is heated, the gap
becomes wider.
Pour a liter of water at 40°C into a liter of water at 20°C and the final temperature of the two becomes
at or about 30°C
In which is the temperature greater?
boiling-hot tea in a cup
Heat energy is measured in units of
both calories and joules
newton's law of cooling applies to objects that...
cool and warm up
Aluminum has a specific heat capacity more than twice that of copper. Place equal masses of aluminum and copper wire in a flame and the one to undergo the fastest increase in temperature will be
copper
When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. The reason for this is
copper expands more than iron.
As a piece of metal with a hole in it cools, the diameter of the hole
decreases
If glass expanded more than mercury, then the column of mercury in a mercury thermometer would fall when the temperature
decreases
It is important that the two metals that compose a bimetallic strip have
different rates of expansion.
the amount of heat transferred to a system can be measured in...
either calories or joules
Internal energy is greater in a
fire-engine pail of boiling-hot tea.
When you touch a hot potato with your finger, energy flows
from the potato to your finger
When you touch a cold piece of ice with your finger, energy flows
from your finger to the ice
In most cases, which expands more for comparable changes in temperature?
gases
The fact that gasoline overflows a full tank on a hot day is evidence that
gasoline expands more with increasing temperature than its tank
To say that water has a high specific heat capacity is to say that water
gives off a lot of energy in cooling
Which of the following contracts most when the temperature is decreased? Equal volumes of
helium
Which of the following expands more when the temperature is increased? Equal volumes of
helium
A substance that heats up relatively slowly has a
high specific heat capacity
The moderate temperatures of islands throughout the world has much to do with water's
high specific heat capacity.
Materials composed of molecules that absorb large amounts of energy in the form of internal vibrations and rotations have
high specific heats.
Which of these expands when the temperature is lowered?
ice water
When the temperature of a strip of iron is increased, the length of the strip
increases
as liquid evaporates, its temperature ________
increases
Which of the following normally warms up fastest when heat is applied?
iron
Which unit represents the most energy?
joule
The amount of heat transferred to a system can be measured in
joules and calories
Temperature is most closely related to molecular
kinetic energy
When an iron ring is heated, the hole becomes
larger
When we enlarge a photograph of an iron ring, the image of the hole becomes
larger
Hot sand cools off faster at night than vegetation. Compared with vegetation, sand's specific heat capacity is...
less
Place a 1-kilogram block of iron at 40°C into 1 kilogram of water at 20°C and the final temperature of the two becomes
less than 30°C
Hot sand cools off faster at night than plants and vegetation. Then, the specific heat capacity of sand is
less than that of plants.
One of water's interesting thermal properties is that when heated it takes a relatively
long time in changing temperature.
The principal source of Earth's internal energy is...
radioactivity
when relatively slow-moving molecules condense from the air, the temp of the remaining air tends to...
remain unchanged
If the specific heat capacity of water were lower than it is, a nice hot bath would be a
shorter experience
If the specific heat capacity of water were lower than it is, a watermelon in a picnic cooler would cool in a
shorter time
T or F: for an engine to produce useable work, the exhaust (output) temperature must be lower than the input temperature
true
T or F: heat never spontaneously flows from a cooler to a warmer body
true
T or F: heat transfer via conduction generally occurs via materials that are poor electrical insulators
true
T or F: the entropy of the universe is increasing
true
T or F: the greater the temp difference between 2 objects, the faster the rate of heat transfer
true
the greenhouse gases that contribute to global warming are...
water vapor and carbon dioxide
when the temp of a strip of iron is increased, the length of the strip
may increase and may decrease
microscopic slush in water tends to make the water...
more dense
If the specific heat of water were lower than it is, ponds in the cold of winter would be
more likely to freeze.
The Farenheit and Centigrade temperature scales have the same numerical value at _____ degrees
-40
The _______ is the amount of heat needed to raise 1 pound of water by one degree F
BTU
Which temperature scales have equal sized degrees
Celsius and Kelvin
State the third law of thermodynamics
In natural processes, high-quality energy tends to transform into lower-quality energy-order tends to disorder
The air in your room is composed of molecules that have
a wide variety of speeds
If you wanted to raise the internal energy of a bucket of 20°C water, you could
add 25°C water in the bucket.
The quantity of heat that a substance can transfer relates to its
all of the above
Heat transfer involving the movement of a hot/cold medium is called _______
convection
heat is simply another word for....
internal energy that flows from hot to cold
Aluminum has a higher specific heat capacity than iron. This means that for equal masses of aluminum and iron, the metal that heats up the fastest is
iron
The white-hot sparks from a 4th-of-July-type sparkler that strike your skin transfer
little energy to you despite of their high temperature.
heat transfer that occurs in the absence of a medium is ________
radiation
the surface of planet earth loses energy to outer space due mostly to...
radiation
an object that absorbs energy well also..
radiates well
as long as water and steam are present the temperature of the water is _____
100 degrees celsius
Which of these temperatures is likely when a container of water at 20°C is mixed with water at 28°C?
22°C
Room temperature on the Kelvin scale is about
300K
The amount of heat needed to raise the temperature of 1 gram of water by 1°C is
4.19 joules
When 10 grams of hot water cool by 1°C, the amount of heat given off is
4.19 joules
Which temperature scale has the smallest sized degrees
Fahrenheit
A temperature difference of 10 Celsius degrees is also equal to a temperature difference of 10 on the
Fahrenheit scale
T or F: heat transfer via conduction is directly proportional to the area of the material
True
T or F: the higher the specific heat of a material, the more heat it takes to raise its temperature
True
T or F: the non-metric unit of heat is the BTU
True
heat comes from the sun to earth by the process of...
radiation
If you measure the width of an outdoor barn with a steel tape on a very cold day, your measured width will be
a bit long
If you measure the distance between two telephone poles with a steel tape on a very hot day, your measured distance will be
a bit short
White-hot sparks from a 4th-of-July-type sparkler that strike your skin have relatively
all of the above
The fact that desert sand is very hot in the day and very cold at night is evidence that the specific heat capacity of sand is relatively
low
a high-temp source radiates relatively
low frequencies of radiation
A substance that heats up relatively quickly has a
low specific heat capacity
A substance that cools down faster than others has a
low specific heat capacity.
The temperature at the top of a waterfall is lower, same, or higher than at the bottom
lower because it gains energy as it falls
The specific heat capacity is highest for substances that absorb or release large quantities of heat for correspondingly
small temperature changes.
A substance with a high thermal inertia has a high
temperature, in many cases.
A closed, sealed can of air placed on a hot stove. The contained air undergoes an increase in
temperature.
In terms of thermal expansion it is important that
the fillings in your teeth expand at the same rate as teeth.
How do down-filled parkas keep you warm?
the fluff/feathers trap air inside, the air heats up inside jacket and keep you warm
Tomatoes have a higher specific heat capacity than dough. This means that when you bite into a hot pizza
the tomato sauce feels hotter than the dough
Heat is simply another word for
thermal energy that flows from hot to cold
The fact that a thermometer "takes its own temperature" illustrates
thermal equilibrium
The kind of molecular motion that mostly relates to the temperature of a substance is
translational motion