Download What Is Tem erature.

What Is Tem erature.
WWilI 11111M-Y10
Name:
How does temperature work? Temperature is a scale
that compares how fast molecules of heat are moving.
When a substance is heated, the temperature rises
because heat makes its molecules move faster. This
is true of water, toast, soup, or an electric wire. There
are two major scales for measuring temperature. The
Fahrenheit scale has 32°F as the freezing point of
water. It sets 212°F as the boiling point of water. A
reading of 0°F is the freezing point of a water and salt
mixture. The inventor of this scale and the first closedtube mercury thermometer was Daniel Fahrenheit. He
did this in 1713. Galileo is credited with inventing the
first working thermometer in 1592.
The Celsius scale measures heat on a scale using 0°C
for the freezing point of water. It has 100°C for the
boiling point of water. Anders Celsius, a Swiss
astronomer, invented the scale in 1742. He first had
0 as the boiling point and 100 as the freezing point. A
famous Swedish biologist named Carolus Linnaeus
switched the scale to what is now in use. The Celsius
thermometer is commonly used in most of the world,
with the exception of the United States and a few
smaller countries.
Scientists use the Celsius scale for ordinary work.
However, in 1842 Lord William Thomson Kelvin
developed the scale most preferred by scientists. In the
Kelvin scale, water boils at 373.2 degrees. It freezes at
273.2 degrees and records absolute zero at 0 degrees.
The lowest possible temperature is called absolute zero.
However, absolute zero can never actually be achieved.
It is a theory based on no movement by molecules at all
and no pressure on molecules in a gas. Absolute zero
on the Fahrenheit scale is -459.7°F. Nothing could live
at that temperature.
What Did You Learn 0
1. What is the equal reading on the Celsius scale for 212°F?
® 0°C
100°C
© 50°C
e
© -273.2°C
2. What is the freezing point of water on the Fahrenheit scale?
® 212°F
© 0°F
0 32°F
© -459.7°F
3. Who switched the Celsius scale to make 0 the freezing point of water and 100 degrees as the boiling point?
C) Anders Celsius
C) Carolus Linnaeus
® Daniel Fahrenheit
• Lord Kelvin
4. Which of the following is a reading for absolute zero?
® -459.7°F
® 0°K
What Am I
• 273.2°C
C) both A and B
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I invented the first-closed tube mercury thermometer and the temperature scale most commonly used today in the
United States.
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Heat is the combined energy created by moving molecules. When you hold your hand above a stove or any source
of heat, the warmth you feel is the movement of billions of fast-moving molecules. The molecules above a cold
fireplace, on the other hand, have not been set in motion. Heat radiates from its source, such as a fireplace, and
heats up the air near the source.
Heat moves in three different ways. Radiation is the spread of heat as rays that are invisible waves. There is no
direct contact with the source. Convection is another method of heat movement. This occurs when warm air rises
through cooler air. The air becomes less dense as it expands, and it is
lighter than the cool air surrounding the warmer air. A hot-air balloon
works because of convection. The warm air rises and lifts the balloon
through the colder air.
Conduction is the movement of heat from hot materials to cold ones. The
moving molecules of warm air crash into the colder molecules, excite
them, and start them moving into other cold molecules. This is why some
parts of a room are warmer than others when you first start a stove or
furnace. The best conductors of heat are metals such as copper and iron.
Feel the metal buttons on a piece of clothing when you are sitting next to a
hot stove or fireplace. They will be much hotter than the cloth. Insulators
are materials that conduct heat more slowly. They retain the heat and
keep things warm. Wood, wool, and water are good insulators.
Directions: Use the information above to answer these questions.
1. Name the three ways that heat moves.
2. What is the term for the combined energy created by moving molecules?
3. What is the movement of heat from hot materials to cold ones called?
4. What is the spread of heat as waves of invisible rays called?
5. What is the movement of warmer air through cooler air called?
6. What form of movement of heat is demonstrated by a burning fire in a fireplace?
7. What form of movement is demonstrated by a hot-air balloon?
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VW gall II II 11-110
Fahrenheit Temperatures
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Name:
Directions: Study the thermometer shown here. Then answer the questions below. This is the thermometer
usually used in daily weather discussions.
Facts to Know
32°F — water freezes
70°F —a warm day
98.6°F — normal hum, n body temperature
212°F — boiling point of water
1. In which of the following temperatures would snow most likely fall?
C) 60°F
e
-30°F
C) 90°F
C) 35°F
2. In which of the following temperatures would snow melt?
® 0°F
C) -40°F
C) 100°F
C) 32°F
3. Which temperature would be best for swimming in an unheated pool?
C) -70°F
® 40°F
() 32°F
© 80°F
4. Which temperature is warm enough to avoid wearing a jacket?
C) 0°F
C) 50°F
75°F
© -20°F
5. Which temperature is most likely to be warm enough to go barefoot comfortably?
C) -20°F
-10°F
C) 80°F
Use the thermometer to compare these temperatures.
1. What temperature is 30 degrees lower than 32°F?
2. What is the boiling point of water?
3. About what temperature is the normal healthy human body?
4. What temperature is the freezing point of water?
5. How many degrees below freezing is 0°F?
6. How many degrees above the freezing point of water is 70°F?
7. How many degrees below the boiling point of water is 100°F?
8. What form (solid, liquid, or gas) does water take at 25°F?
9. What form does water take at 50°F?
10. Could you drink water from a glass at 0°F?
C) 60°F
vv. II 111 111-1010
Celsius and Fahrenheit
Comparisons
Nar
Directions: Answer the questions related to the two systems of measurement.
water boils—IP-2121. Which temperature is warmer, 0°F or 0°C?
2. Which temperature is colder, 0°C or 32°F?
194-
-90
176-
- 80
158-
-70
140-
-60
122-
-50
104-
normal body-o- 9
86temperature
3. At which temperature would water boil, 212°F
or 90°C?
-100
-40
-37-4—normal body
-30
temperature
68-
-20
50-
-10
water freezes--32-
-0-4— water freezes
FAHRENHEIT CELSIUS
4. What is the normal temperature of the human body in degrees Fahrenheit?
5. About what is the normal temperature of the human body in degrees Celsius?
6. How far from freezing is a 50° reading on a Celsius thermometer?
7. How far from freezing is a 50° reading on a Fahrenheit thermometer?
8. Would you be colder at a Celsius reading of 50° or a Fahrenheit reading of 50°?
9. Would you be warmer at a Celsius reading of 100° or a Fahrenheit reading of 100°?
10. Which temperature is more comfortable for a human, 0°C or 0°F?
11. Which temperature would you find less comfortable, 70°F or 70°C?
12. Which temperature would prevent snow from melting, 25°F or 25°C?
-water boils
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Graphing Temperatures
Name:
Temperatures
70°
60°
50°
40°
30°
20°
10°
.
.100
.200
March
1
2
3
4
5
6
7
8
10
9
11
12
Directions: Study the graph of temperatures for the first 12 days of March in one northern state. Answer the
questions below the graph.
1. Which two days in March were the coldest?
2. Which day was the warmest?
3. How many days did the temperature go above 0 degrees?
4. Which part of the month had the warmest temperatures the first 6 days or the second 6 days?
5. How many days were 30 degrees or lower?
6. How many days were 0 degrees or below?
7. How many days were 30 degrees or higher?
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MI II II 1-‘010
IWO
rd Study
Name:
Directions: Read and study the following vocabulary words and definitions. Then use each word in a sentence
that relates to the information from this unit.
convection — heat currents that move through air or water; air rises with heat
conduction — a way to transfer heat by touching solid materials
radiation — the spread of heat by invisible waves of infrared radiation, without direct contact
insulators — materials that conduct heat slowly, such as wood, water, and wool
conductors — solid materials that transfer heat
IN T at Is Energy?
11111%1111 11111111-41010 WNW
Name:
What is energy? It is the ability to make things happen. I of energy are a snowball rolling down a hill, a car in
The total amount of energy in the universe has stayed
motion, or a falling baseball.
the same since the very first moment in time. Energy is
Energy cannot be destroyed, but it can be burned up.
never really lost or gained. It just moves or changes.
Energy, which is converted to heat, is not destroyed.
Energy does its work either by transfer from one form of
However, it is hard to use again because the heat
energy to another or by conversion. The transfer of
spreads out in all directions. Energy cannot be reused
energy occurs when energy moves from one place to
once it has been turned to heat. Scientists call energy
another. When heat rises or a football is kicked, energy
that has become unusable "entropy." Energy moves
is transferred. Conversion of energy happens when
from areas of high energy to areas of low energy and
wind power produces electricity or coal is burned to
from areas of heat to areas of cold. The nature of
produce heat.
energy is summed up in two laws of thermodynamics.
Scientists define two broad types of energy. One is
The first law says that the total energy of the universe
potential energy. This type of energy is stored up and
was fixed forever at the beginning of time. The second
ready to use. Examples of this energy are a squeezed
law says that energy is lost every time it is used. So
spring ready to snap out or an object ready to fall.
entropy in the universe keeps increasing.
Kinetic energy is moving energy. Examples of this kind
What Did You Learn
1. The ability to make things happen is a definition of what scientific term?
C) energy
® entropy
8 electricity
C) conversion
2. Energy accomplishes work or makes things happen in which way?
0 heat
® conversion
C) transfer
C) both A and B
3. What word is used to describe energy that cannot be used?
0 high energy
C) entropy
C) electrical
C) both A and B
4. Which law of thermodynamics says that the amount of energy in the universe was fixed forever since the
dawn of time?
® fourth
© third
® first
0 second
What Am 1
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6
Two laws about me sum up the nature of energy.
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Potent al and Kineic
Energy
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Potential Energy
Potential energy refers to energy that is stored in some way, but ready to use. A stretched rubber band, an apple
ready to fall from a tree, and a spring that is stretched are forms of potential energy. So is food stored in an
organism and ready to use.
Kinetic Energy
Kinetic energy is demonstrated in moving objects. The word kinetic means "moving or resulting from motion." A
moving rubber band when it is snapped, a falling apple from a tree, and a spring that is in motion are examples of
kinetic energy.
Directions: Identify each energy example below as potential (P) or kinetic (K) energy.
12.
a piece of wood before it goes
into the fire
13.
a piece of wood burning in
the fireplace
a hammer in motion towards a nail
14.
a berry before it is eaten by a bird
5.
a spring being sat on
15.
6.
a fully stretched rubber band
a berry after it has been eaten by
a bird
7.
a branch being held back
16.
cold water sitting on a stove
8.
a branch being let go
17.
water that is steaming and boiling
9.
a stretched rubber band when
it is let go
18.
a cheetah running at full speed
19.
a cheetah waiting to spring on
its prey
20.
a hammer sitting on a table
1.
a ripe orange hanging from a tree
2.
a skateboard at the top of a hill
3.
a car waiting to start a race
4.
10.
a light bulb before it is turned on
11.
a light bulb that is lit