An inventor develops a stationary cycling device by which an individual, while pedaling, can convert all of the energy expended into heat for warming water. How much mechanical energy is required to increase the temperature of 300 gm of water (enough for

1
An inventor develops a stationary cycling device
by which an individual, while pedaling, can
convert all of the energy expended into heat for
warming water. How much mechanical energy is
required to increase the temperature of 300 gm of
water (enough for 1 cup of coffee) from 20C to
95C? (1 cal 4.186 J)

1. 94,000 Joules
2. 22,000 Joules
3. 5400 Joules
4. 13.9 Joules

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
2
An inventor develops a stationary cycling device
by which an individual, while pedaling, can
convert all of the energy expended into heat for
warming water. What minimum power must be
generated if 300 gm water (enough for 1 cup of
coffee) is to be heated in 10 min from 20C to
95C? (1 cal 4.186 J)

1. 9400 watts
2. 586 watts
3. 160 watts
4. 31 watts

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
3
A falling 500 kg object is attached by a rope
through a pulley to a paddle wheel shaft which is
placed in a well-insulated tank holding 25 kg of
water. The object, in being allowed to fall,
causes the paddle wheel to rotate to churn the
water. If the object falls a vertical distance of
100 m at constant speed, what is the temperature
change of the water? (1 Kcalorie 4186 J and g
9.8 m/s2 )

1. 19600C
2. 4700C
3. 4.7C
4. 0.8C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
4
Sea breezes that occur near the shore are
attributed to a difference between land and water
with respect to what property?

1. mass density
2. coefficient of volume expansion
3. specific heat
4. emissivity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
5
Which of the following processes of heat transfer
may take place in a vacuum?

1. conduction
2. radiation
3. convection
4. None of these choices are valid

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
6
Which one of the following processes of heat
transfer require the presence of a fluid?

1. conduction
2. radiation
3. convection
4. None of these choices are valid

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
7
If cooking is done using an aluminum pan over an
electric burner, which of the following will not
promote the rate of heat flow from burner to food?

1. increase pan bottom thickness
2. increase pan bottom area
3. increase burner temperature
4. decrease height of pan sides

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
8
The first experiment which systematically
demonstrated the equivalence of mechanical energy
and heat was performed by which of the following
scientists?

1. Joule
2. Boltzmann
3. Thompson, Count Rumford
4. Kelvin

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
9
On a sunny day at the beach, the reason the sand
gets so hot and the water stays relatively cool
is attributed to the difference in which property
between water and sand?

1. mass density
2. specific heat
3. temperature
4. thermal conductivity

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
10
The surfaces of a Dewar flask are silvered for
the purpose of minimizing heat transfer by what
process?

1. conduction
2. radiation
3. convection
4. vaporization

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
11
The use of fiberglass insulation in the outer
walls of a building is intended to minimize heat
transfer through what process?

1. conduction
2. radiation
3. convection
4. vaporization

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
12
A 200 gm mass of metal with a specific heat of
0.30 cal/gm-C, initially at 90C, is placed in a
500 gm calorimeter initially at 20 C with a
specific heat of 0.10 cal/gm-C. The calorimeter
is filled with 100 gm of water initially at 20C.
Once the combination of metal, calorimeter and
water reach equilibrium, what is the final
temperature?

1. 70C
2. 60C
3. 50C
4. 40C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
13
Heat flow occurs between two bodies in thermal
contact when they differ in what property?

1. mass
2. specific heat
3. density
4. temperature

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
14
If one's hands are being warmed by holding them
to one side of a flame, the predominant form of
heat transfer is what process?

1. conduction
2. radiation
3. convection
4. vaporization

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
15
The first experimental observation which tended
to disprove the caloric model of heat was made by
which of the following scientists?

1. Joule
2. Boltzmann
3. Thompson, Count Rumford
4. Kelvin

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
16
A 20 gm object has what specific heat if its
temperature increases by 5C when 20 cal of heat
are transferred to it?

1. 0.20 cal/gm-C
2. 0.40 cal/gm-C
3. 0.60 cal/gm-C
4. 0.85 cal/gm-C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
17
In a greenhouse, electromagnetic energy in the
form of visible light enters the glass panes and
is absorbed and then reradiated. What happens to
this reradiated electromagnetic radiation from
within the greenhouse?

1. 100 returns to the atmosphere
2. blocked by glass
3. transformed into ultraviolet upon striking the
   glass
4. reflected as visible light upon striking the glass

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
18
Which of the following best describes a substance
in which the temperature remains constant while
at the same time it is experiencing an inward
heat flow?

1. gas
2. liquid
3. solid
4. substance undergoing a change of state

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
19
A copper rod has one of its ends placed in a
Bunsen flame and the other end embedded in an ice
cube. By what factor is the rate of heat flow
changed when the rod length is tripled?

1. 0.33
2. 1/9
3. 3.0
4. 9.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
20
A copper rod has one of its ends placed in a heat
reservoir and the other end in a heat sink. By
what factor is the rate of heat flow changed when
the temperature difference between the reservoir
and sink is tripled?

1. 0.33
2. 1/9
3. 3.0
4. 9.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
21
The surface of the sun has a temperature of about
5800 K. If the radius of the sun is 7 x 108 m,
determine the power output of the sun. (Take S
1, and s 5.67 x 10-8 W/m2 /K4 )

1. 3.95 x 1026 W
2. 5.17 x 1027 W
3. 9.62 x 1028 W
4. 6.96 x 1030 W

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
22
The tungsten filament of a lightbulb has an
operating temperature of about 2100 K. If the
emitting area of the filament is 1 cm2 , and its
emissivity is 0.68, what is the power output of
the lightbulb? (s 5.67 x 10-8 W/m2 x K4 )

1. 100 W
2. 75 W
3. 60 W
4. 40 W

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
23
A 5 - gram lead bullet traveling in 20C air at
300 m/s strikes a flat steel plate and stops.
What is the final temperature of the lead bullet?
(Assume all heat is retained by the bullet). The
melting point of lead is 327C. The specific
heat of lead is 0.122 J/g/C. The heat of fusion
of lead is 24.7 J/g.

1. 227C
2. 260C
3. 293C
4. 327C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
24
A slice of bread contains about 100
kilo-calories. If the specific heat of a person
is 1 kilocalorie/kg xC, by how many C would the
temperature of a 70-kg person increase if all the
energy in the bread were converted to heat?

1. 2.25C
2. 1.86C
3. 1.43C
4. 1.00C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
25
At high noon, the sun delivers 1000 watts to each
square meter of a blacktop road. What is the
equilibrium temperature of the hot asphalt? (s
5.67 x 10-8 W/m2 / K4 )

1. 75C
2. 84C
3. 91C
4. 99C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
26
A silver bar of length 30 cm and cross-sectional
area 1 cm2 is used to transfer heat from a 100C
reservoir to a 0C block of ice. How much ice is
melted per second? (For silver, k 427 W/m x C.
For ice, Lf 334,000 J/kg.)

1. 4.2 grams/s
2. 2.1 grams/s
3. 0.8 grams/s
4. 0.042 grams/s

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
27
Find the final equilibrium temperature when 10
grams of milk at 10C is added to 160 grams of
coffee at 90C. (Assume the specific heats of
coffee and milk are the same as water and neglect
the heat capacity of the container).

1. 85.3C
2. 77.7C
3. 71.4C
4. 66.7C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
28
How much heat energy is required to vaporize a 1
- gram ice cube at 0C? The heat of fusion of ice
is 80 calories/gram. The heat of vaporization of
water is 540 cal/gram.

1. 620 calories
2. 720 calories
3. 820 calories
4. 1 kilocalorie

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
29
How much heat energy must be removed from 100
grams of oxygen at 22C to liquify it at -183C?
(The specific heat of oxygen gas is 0.218
cal/g-C and its heat of vaporization is 50.9
cal/gram.)

1. 13,652 cal
2. 9,559 cal
3. 4,316 cal
4. 2,160 cal

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
30
100 grams of liquid nitrogen at 77 K is stirred
into a beaker containing 500 grams of 15C water.
If the nitrogen leaves the solution as soon as it
turns to gas, how much water freezes? The heat of
vaporization of nitrogen is 48 cal/gram. The heat
of fusion of water is 80 cal/gm.

1. none
2. 29 grams
3. 68 grams
4. 109 grams

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
31
In winter, light colored clothes will keep you
warmer than dark colored clothes if

1. you are warmer than your surroundings.
2. you are at the same temperature as your
   surroundings.
3. you are cooler than your surroundings.
4. you are standing in sunlight.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
32
I take 1 kg of ice and dump it into 1 kg of water
and, when equilibrium is reached, I have 2 kg of
ice. The water was originally at 0C. The
specific heat of water 1 kcal/kg-C, the
specific heat of ice 0.5 kcal/kg-C, and the
latent heat of fusion of water is 80 kcal/kg-C.
The original temperature of the ice was

1. one or two degrees below 0C
2. -80C
3. -160C
4. the whole experiment is impossible.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
33
Consider two different rods and predict which
will have the greatest thermal conductivity. The
rod with

1. electrons that are freer to move from atom to
   atom.
2. the greater specific heat.
3. the greater cross-sectional area.
4. the greater length.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
34
Which type of heating causes sunburn?

1. conduction
2. convection
3. radiation
4. all of these cause sunburn

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
35
Carbon dioxide and water molecules in the
atmosphere will absorb

1. infrared light.
2. visible light.
3. ultraviolet light.
4. radio waves.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
36
In a cloud formation, water vapor turns into
water droplets which get bigger and bigger until
it rains. This will cause the temperature of the
air in the clouds to

1. get warmer.
2. get cooler.
3. will not affect the temperature of the air in the
   clouds.
4. there is no air in clouds.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
37
Active solar heating involves the use of

1. convection currents.
2. air locks.
3. pumps.
4. the greenhouse effect.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
38
A 120-gram block of copper is taken from a kiln
and carefully placed into a beaker containing 300
grams of water. The water temperature rises from
15C to 35C. Given cCu 0.10 cal/gram-C, and
cwater 1.00 cal/gram-C, what was the
temperature of the kiln?

1. 500C
2. 360C
3. 720C
4. 535C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
39
125 grams of dry ice (solid CO2 ) is dropped into
a beaker containing 500 grams of 66C water. The
dry ice converts directly to gas, leaving the
solution. When the dry ice is gone, the final
temperature of the water is 29C. What is the
heat of vaporization of solid CO2 ?

1. 37 cal/gram
2. 74 cal/gram
3. 111 cal/gram
4. 148 cal/gram

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
40
A piece of copper of mass 100 grams is being
drilled through with a 1/2" electric drill. The
drill operates at 40 W and takes 30 seconds to
bore through the copper. The specific heat of
copper is 387 J/kg-C. Find the increase in its
temperature.

1. 40.6C
2. 34.7C
3. 31.0C
4. 27.3C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
41
As I use sandpaper on some rusty metal, the
sandpaper gets hot.

1. Heat is flowing from the sandpaper into the
   metal.
2. Heat is flowing from the metal into the
   sandpaper.
3. Friction is creating the heat.
4. Heat is flowing from my hand into the sandpaper.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
42
A 50 gm cube of ice, initially at 0C is dropped
into a 200 gm of water in an 80 gm aluminum
container, both initially at 30C. What is the
final equilibrium temperature? (Specific heat for
aluminum is 0.215 cal/gm-C and Lf 80 cal/gm.)

1. 17.9C
2. 9.4C
3. 12.1C
4. 20.6C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
43
If heat is flowing from a table to a block of ice
moving across the table, which of the following
must be true?

1. The table is rough and there is friction between
   the table and ice.
2. The ice is cooler than the table.
3. The ice is changing phase.
4. All three are possible, but none is absolutely
   necessary.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
44
A 500 gm ice cube, initially at 0C, is placed in
a styrofoam box whose wall thickness is 1.0 cm
and the total surface area is 600 cm2 . If the
air surrounding the box is at 20C and after 4
hours the ice is completely melted, what is the
conductivity of the styrofoam material? (Lf 80
cal/gm)

1. 9.6 x 10-5 cal/cm-sec-C
2. 2.8 x 10-6 cal/cm-sec-C
3. 1.15 x 10-2 cal/cm-sec-C
4. 2.3 x 10-4 cal/cm-sec-C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
45
A solar heating system has a 25 conversion
efficiency the solar radiation incident on the
panels is 1000 W/m2. What is the increase in
temperature of 30 kg of water in a 1.0 hr period
by a 4.0 m2 area collector?

1. 14.3C
2. 22.4C
3. 28.6C
4. 44.3C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
46
A 100 gm piece of copper, initially at 95C, is
dropped into 200 gm of water contained in a 280
gm aluminum calorimeter the water and
calorimeter are initially at 15C. What is the
final temperature of the system? (specific heats
of copper and aluminum of 0.092 and 0.215
cal/gm-C, respectively)

1. 16.8C
2. 18.3C
3. 23.7C
4. 25.0C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
47
A machine gear consists of 0.1 kg of iron and
0.16 kg of copper. How much total heat is
generated in the part if its temperature
increases by 35C? (Specific heats of iron and
copper are 0.11 and 0.092 kcal/kg/C,
respectively, and 1 kcal 4186 J.)

1. 910 J
2. 3770 J
3. 3980 J
4. 4420 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
48
What is the temperature increase of 4.0 kg of
water when heated by a 800 W immersion heater for
10 min?

1. 56C
2. 51C
3. 28C
4. 14C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
49
Iced tea is made by adding ice to 1.8 kg of hot
tea, initially at 80C. How many kg of ice,
initially at 0C, are required to bring the
mixture to 10C? (Lf 80 kcal/kg)

1. 1.8 kg
2. 1.6 kg
3. 1.4 kg
4. 1.2 kg

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
50
The filament temperature of a light bulb is 2000
K when the bulb delivers 40 W of power. If its
emissivity remains constant, what power is
delivered if the filament temperature is raised
to 2500 K?

1. 105 W
2. 62 W
3. 98 W
4. 50 W

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51
A waterfall is 145 m high. What is the increase
in temperature of the water at the bottom of the
falls if all of the initial potential energy goes
into heating the water? (g 9.8 m/s2 and 1 kcal
4186 J)

1. 0.16C
2. 0.34C
3. 0.69C
4. 1.04C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
52
A 0.2 kg aluminum plate, initially at 20C,
slides down a 15 m long surface, inclined at a
30 angle to the horizontal. The force of kinetic
friction exactly balances the component of
gravity down the plane so that the plate, once
started, glides down at constant velocity. If 90
of the mechanical energy of the system is
absorbed by the aluminum, what is its temperature
increase when at the bottom of the incline?
(Specific heat for aluminum is 0.215 kcal/kg/C
and 1 kcal 4186 J)

1. 0.16C
2. 0.08C
3. 0.04C
4. 0.03C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
53
How many kilo-watt hours of energy would be
required to raise the temperature of a 30,000
gallon swimming pool by 5C? (One gallon of
water has a mass of approximately 3.8 kg and the
specific heat of water is 4186 J/kgxC.)

1. 1047.7 kWH
2. 662.8 kWH
3. 330.0 kWH
4. 216.6 kWH

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
54
A solar heated house loses about 5.4 x 107 cal
through its outer surfaces on a typical 24 hr
winter day. What mass of storage rock is needed
to provide this amount of heat if it is brought
up to initial temperature of 62C by the solar
collectors and the house is maintained at 20C?
(Specific heat of rock is 0.21 cal/gm-C.)

1. 163 kg
2. 1,230 kg
3. 6,100 kg
4. 12,700 kg

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
55
A 2-m2 thermopane window is constructed, using
two layers of glass 4 mm thick, separated by an
air space of 5 mm. If the temperature difference
is 20 from the inside of the house to the
outside air, what is the rate of heat flow
through this window? (Thermal conductivity for
glass is 0.8 J/s x m x C and for air 0.0234 J/s
x m x C.)

1. 8000 W
2. 2000 W
3. 568 W
4. 179 W

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
56
A 0.003 kg lead bullet is traveling at a speed of
240 m/s when it embeds in a block of ice at 0C.
If all the heat generated goes into melting ice,
what quantity of ice is melted? (Lf 80
kcal/kg, the specific heat of lead 0.03 kcal/kg
C, and 1 kcal 4186 J)

1. 1.47 x 10-2 kg
2. 5.8 x 10-4 kg
3. 3.2 x 10-3 kg
4. 2.6 x 10-4 kg

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
57
A flat pan container holds 200 gm of water. If
over a 10 min period, 1.5 gm of water evaporates
from the surface, what is the approximate
temperature change of the remaining water? (Lv
540 cal/gm)

1. 4C
2. -4C
3. 0.4C
4. -0.4C

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
58
A glass pane 0.4 cm thick has an area of 2 m2 .
On a winter day the temperature difference
between the inside and outside surfaces of the
pane is 20C. What is the rate of heat flow
through this window? (Thermal conductivity for
glass is 0.8 J/s x m x C.)

1. 32,000 J/s
2. 8,000 J/s
3. 4,000 J/s
4. 1,000 J/s

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
59
A 0.003 kg lead bullet is traveling at a speed of
240 m/s when it embeds in a wood post. If it
assumed that half of the resultant heat energy
generated remains with the bullet, what is the
increase in temperature of the embedded bullet?
(Specific heat of lead 0.03 kcal/kg- C, 1 kcal
4186 J.)

1. 115
2. 137
3. 230
4. 259

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50