AP® Physics 2
Myers Park High School
Problem Set: Thermal Energy and Heat
A. Sensible Heat
1.
2.
3.
4.
5.
6.
7.
8.
9.
1)
6)
How much heat is absorbed by 250.0 g of water when it is heated from 10.0C to 85.0C?
How much heat is absorbed by 60.0 g of copper when it is heated from 20.0C to 80.0C?
A 38.0 kg block of lead is heated from -26C to 180.C. How much heat does the lead absorb?
The cooling system of an automobile engine contains 20.0 L of water. (One liter of water has a
mass of one kilogram.) What is the change in temperature of the water if the engine operates
until 836.0 kJ of heat are added
Suppose the engine in question # 4 was filled with methanol whose density is 0.800 g/cm3. What
increase in temperature would occur if the methanol absorbed the same 836.0 kJ of heat? Which is
a better coolant: water or methanol? (Hint: 1 L = 1000 cm3)
A 400.0 g glass coffee cup (C = 0.837 J/gC) at room temperature, 20.C, is plunged into hot
dishwater at 80.C. If the temperature of the cup reaches that of the dishwater, how much heat does
the cup absorb?
Five kilograms of ice cubes are moved from the freezing compartment of a refrigerator into a home
freezer. The refrigerator's freezing compartment maintains a temperature of -4.0C. The home
freezer is kept at -17C. How much heat does the freezer's cooling system remove from the ice
cubes?
A 250.0 kg cast iron car engine contains water as a coolant. Suppose the engine's temperature is
35.0C when it is shut off. The air temperature is 10.0C. The heat given off by the engine and the
water in it as they cool to air temperature is 4400. kJ. What mass of water is used to cool the
engine? You may assume that the temperature of the water and the temperature of the engine are
always equal.
An 800.0 g block of unknown metal is heated in boiling water and then removed to a Styrofoam cup
filled with room temperature water. The metal loses 8150 J of heat to the water as its temperature
changes by 80.0C. What is the specific heat and the identity of the metal?
78.4 kJ
20 kJ
2)
7)
1400 J
133 kJ
3)
8)
1.02 x 10 6 J
15.2 kg
4)
9)
10.0C
5)
0.127 J/gC; lead
21.5C; water
B. Heat Transfer
1.
2.
3.
4.
5.
6.
7.
8.
Suppose the same amount of heat needed to raise the temperature of 50.0 g of water from 0C to
100.C is added to 50.0 g of zinc. What is the temperature change for the zinc?
A 200.0 g sample of water at 80.0C is mixed with 200.0 g of water at 10.0C in a Styrofoam cup.
What is the final temperature of the water mixture?
A 600.0 g sample of water at 90.0C is added to 400.0 g of water at room temperature (22.0C).
What is the final temperature of the mixture if no heat is lost to the surroundings?
A 400.0 g sample of ethyl alcohol at 16C is mixed with 400.0 g of water at 85C in a coffee cup
calorimeter. What is the final temperature of the mixture?
A 100.0 g piece of copper heated to 90.0C is placed in a Styrofoam cup containing 200.0 g of
water at 20.0C. What is the temperature when thermal equilibrium is achieved?
A 10.0 kg piece of zinc at 71.0C is placed in an insulated container containing 20.0 kg of water at
10.0C. What is the final temperature of the zinc?
A 100.0 g mass of an unknown metal at 100.0C is transferred to a coffee cup calorimeter
containing 100.0 g of water at 10.0C. Thermal equilibrium is reached at 25.0C. What is the
specific heat of the metal?
A 100.0 g sample of an unknown metal at 100.0C is placed in 200.0 g of water at 20.0C. The
final temperature of the mixture is 21.6C. Determine the specific heat of tungsten.
AP® Physics 2
Myers Park High School
9.
Problem Set: Thermal Energy and Heat
What mass of water at room temperature (25.0C) is required to cool a 200.0 g piece of lead from
85.0C to 30.0C?
Use the table below for questions 10-15.
Substance
aluminum
copper
glass
gold
iron
lead
silver
Specific Heat
(J/kgC)
900
387
837
129
448
128
234
Note: For the following problems, neglect any heat transfer to or from the surroundings.
10.
A 400.0 g iron horseshoe initially at 500.0C is dropped into a bucket containing 20.0 kg of water at
22C. What is the equilibrium temperature?
11.
A 400.0 g sample of an unknown liquid at 80.0C is poured into 400.0 g of water at 40.0C. The
final equilibrium temperature of the mixture is 49.0C. What is the specific heat of the liquid?
12.
What mass of water at 25C must be allowed to reach thermal equilibrium with a 3.0 kg gold bar at
100C in order to lower the temperature of the bar to 50C?
13.
A block of copper of mass 200.0 g at a temperature of 90.0C is dropped into 400.0 g of water at
27C. The water is contained in a 300.0 g glass container that remains in thermal equilibrium with
the water. What is the final temperature of the mixture?
14.
An aluminum cup contains 225 g of water at 27C. A 400.0 g sample of silver at an initial
temperature of 87C is placed into the water. A 40.0 g copper stirrer initially sitting in the water is
used to stir the mixture until it reaches it final equilibrium temperature of 32C. Calculate the mass
of the aluminum cup.
15.
In a foundry operation, molten lead of mass 90.0 g at 327.3C is poured into an iron casting block
that has a mass of 300.0 g and initially at 20.0C. What is the equilibrium temperature of the
system?
1)
6)
1080C
12.7C
10)
13)
23C
29.4C
2)
7)
45.0C
0.836 J/gC
11)
14)
3)
8)
62.8C
0.171 J/gC
1215 J/kgC
81.8 g
4)
9)
59.6C
68.4 g
12)
15)
5)
185 g
56.5C
23.1C
AP® Physics 2
Myers Park High School
Problem Set: Thermal Energy and Heat
C. Phase Changes
Water
334 J/g
2260 J/g
Heat of fusion
Heat of vaporization
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
1)
6)
Mercury
11.5 J/g
272 J/g
How much heat must be absorbed to change 50.0 g of ice at 0C to water at 0C?
How much heat is released when 50.0 g of steam at 100C is condensed to water at 100C?
How much heat is absorbed by 100.0 g of ice at –20.0C to become water at 0C?
A 200.0 g sample of water at 60.0C is heated to steam at 140.0C. How much heat was
absorbed?
How much heat is needed to change 300.0 g of ice at –30.0C to steam at 130.0C?
How much heat is removed from 60.0 g of steam at 100.0C when it is changed to water at
20.0C?
The specific heat of liquid mercury is 0.140 J/gC. How much heat is needed to take 1.00 kg of
mercury from 10.0C to its boiling point (357C) and completely vaporize the mercury?
Years ago, a block of ice with a mass of 20.0 kg was used daily in a home icebox. The
temperature of the ice was 0C when it was delivered. As it melted, how many joules of heat did
a block this size absorb?
A 40.0 g sample of chloroform is condensed from vapor at 61.6C to a liquid at 61.6C. This
condensation liberates 9870 joules of heat. What is the heat of vaporization of chloroform?
A 50.0 g sample of ice at 0C is placed in a coffee-cup calorimeter containing 400.0 g of water at
50.0C. What is the final temperature of the mixture?
16.7 kJ
156 kJ
2)
7)
1.13 x 105 J
319 kJ
3)
8)
37.5 kJ
6680 kJ
4)
9)
502 kJ
247 J/g
5)
10)
940 kJ
35.6C