Download Chapter 10-11 review [Physics]

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Chapter 10-11 review [Physics]
Vocabulary:
1. Thermal Energy
2.
3.
4.
5.
6.
7.
8.
9.
10.
Conduction
Convection
Radiation
Temperature
Heat
Specific heat
Calorimeter
Conservation of Energy
Boiling/Vaporization
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
Latent Heat of vaporization
Melting
Latent Heat of Fusion
First Law of Thermodynamics
Second Law of Thermodynamics
Entropy
Adiabatic
Isovolumetric
Isothermal
Isobaric
Multiple Choice:
1. Which of the following is proportional to the kinetic energy of atoms and molecules?
a. elastic energy
b. temperature
c. potential energy
d. thermal equilibrium
2. Heat flow occurs between two bodies in thermal contact when they differ in which of the following
properties?
a. mass
b. density
c. specific heat
d. temperature
3. If two small beakers of water, one at 20 ºC and one at 30 ºC, are emptied into a large beaker, what
is the final temperature of the water?
a. less than 20 ºC
b. between 20 ºC and 30 ºC
c. greater than 30 ºC
d. The water temperature will fluctuate.
4. Jacob takes six ice cubes from the freezer and puts four of them into a glass of water. He leaves
two on the counter-top. He stirs the water until the ice cubes are much smaller and have just
stopped melting. What is the most likely temperature of the water at this stage?
a. -10 ºC
b. 0 ºC
c. 5 ºC
d. 10 ºC
5. The ice cubes Jacob left on the counter are now almost completely melted and lying in a puddle of
water. What is the most likely temperature of these smaller ice cubes?
a. -10 ºC
b. 0 ºC
c. 5 ºC
d. 10 ºC
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6. On the stove is a kettle full of water. The water has started to boil rapidly. The most likely
temperature of the water is about
a. 88 ºC
b. 98 ºC
c. 110 ºC
d. None of the above
7. Five minutes later, the water in the kettle is still boiling. The most likely temperature of the
water is about
a. 88 ºC
b. 98 ºC
c. 110 ºC
d. 120 ºC
8. What is the likely temperature of the steam above the boiling water in the kettle?
a. 88 ºC
b. 98 ºC
c. 110 ºC
d. 120 ºC
9. Erika takes two cups of water at 40 ºC and mixes them with one cup of water at 10 ºC. What is the
most likely temperature of the mixture?
a. 20 ºC
b. 25 ºC
c. 30 ºC
d. 50 ºC
10. Gracie takes a can of coke and plastic bottle of coke from the refrigerator, where they have both
been overnight. She quickly puts a thermometer in the can. The temperature is 7 ºC. What are
the most likely temperatures of the plastic bottle and its contents?
a. The are both less than 7 ºC
b. They are both at 7 ºC
c. They are both greater than 7 ºC
d. It depends on the size of the bottle
11. Melanie wants to know why people wear sweater in cold weather. Who is correct in terms of
physics?
a. Kelly answers, “because we look good in them.”
b. Ashlan adds, “it would be stupid to wear a sweater in the summer.”
c. Sarah says, “my dog wears a sweater.”
d. Jeff replies, “it reduces heat loss.”
12. Energy transferred as heat always moved from an object
a. at low temperature to an object at high temperature.
b. at high temperature to an object at low temperature.
c. at low kinetic energy to an object at high kinetic energy.
d. of higher mass to an object of lower mass.
13. Which of the following is a thermodynamic process during which work is done on or by the system
but no energy is transferred to or from the system as heat?
a. adiabatic process
b. isovolumetric process
c. isothermal process
d. isobaric process
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14. During an isovolumetric process, which of the following does not change?
a. volume
b. heat
c. temperature
d. pressure
15. During an isothermal process, which of the following does not change?
a. volume
b. heat
c. temperature
d. pressure
16. In what two ways can you increase the efficiency of a heat engine? Raise Tin, lower Tout
17. What is entropy? Measure of disorganization of a system.
18. Heat added at a constant rate to a sample of a pure substance that is initially a solid at
temperature T0. The temperature of the sample as a function of time is shown in the graph to the
right.
T or F
a. F substance sublimes directly
from the solid phase to the vapor
phase
b. F melting point is T2
Temperature
c. T specific heat is greater for the
T2
liquid phase than for the solid
phase
T1
d. F heat of fusion and heat of
vaporization are equal
T0
e. T Boiling point is T2
Time
f. F Below T0 the substance is liquid
g. T Lv is greater than Lf
19.
A chunk of ice with a mass of 1 kg at 0°C melts and absorbs 3.35 x 108 J of heat in the
process. Which best describes what happened to this system?
a. Its entropy increased.
c. Its entropy remained constant.
b. Its entropy decreased.
d. Work was converted to energy.
20. According to the second law of thermodynamics, which of the following applies for any
process that can occur within an isolated system?
a. Entropy remains constant.
c. Entropy decreases.
b. Entropy increases.
d. Entropy equals work done.
21. When an egg is broken and scrambled, the entropy of the system
a. increases, and the total entropy of the universe increases.
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b. decreases, and the total entropy of the universe increases.
c. increases, and the total entropy of the universe decreases.
d. decreases, and the total entropy of the universe decreases.
22. When a drop of ink mixes with water, the entropy of the system
a. increases, and the total entropy of the universe increases.
b. decreases, and the total entropy of the universe increases.
c. increases, and the total entropy of the universe decreases.
d. decreases, and the total entropy of the universe decreases.
23. When all
a.
b.
c.
d.
24. How
a.
b.
c.
d.
the entropy changes in a process are included,
the increases in entropy are always less than the decreases.
the increases in entropy are always equal to the decreases.
the increases in entropy are always greater than the decreases.
the increases in entropy can be greater or less than the decreases.
is conservation of internal energy expressed for an isothermal system?
Q = W = 0, so ΔU = 0
Q = 0, so ΔU = –W
ΔT = 0, so ΔU = 0; therefore, ΔU = Q – W = 0, or Q = W
ΔV = 0, so PΔV = 0 and W = 0; therefore, ΔU = Q
25. According to the first law of thermodynamics, the difference between energy
transferred to or from a system as heat and energy transferred to or from a system by
work is equivalent to which of the following?
a. entropy change
c. temperature change
b. internal energy change
d. specific heat
26. Sunlight strikes an ice cube at its melting point and causes it to melt. What is this
process?
a. adiabatic process
c. isobaric process
b. isothermal process
d. isovolumetric process
27. Which of the following is a thermodynamic process during which work is done on or by
the system but no energy is transferred to or from the system as heat?
a. adiabatic process
c. isovolumetric process
b. isothermal process
d. isobaric process
28. Which of the following processes for an ideal gas system has an unchanging internal
energy and a heat intake that corresponds to the value of the work done by the
system?
a. isothermal process
c. adiabatic process
b. isobaric process
d. isovolumetric process
29. Which of the following is a thermodynamic process that takes place at a constant
temperature and in which the internal energy of a system remains unchanged?
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a. adiabatic process
b. isothermal process
c. isovolumetric process
d. isobaric process
30. The figure above shows how the temperature of 10.0 g of ice changes as energy is
added. Which of the following statements is correct?
a. The water absorbed energy continuously, but the temperature increased
only when all of the water was in one phase.
b. The water absorbed energy sporadically, and the temperature increased only
when all of the water was in one phase.
c. The water absorbed energy continuously, and the temperature increased
continuously.
d. The water did not absorb energy.
31. A 3.0 x 10–3 kg lead bullet is traveling at a speed of 240 m/s when it becomes
embedded in a block of ice with a temperature of 0.0°C. If all the heat generated goes
into melting the ice, what quantity of ice is melted? (Lf = 3.4 x 105 J/kg and
clead = 1.3 x 102 J/kg°C)
a. 1.5 x 10–2 kg
c. 3.2x 10–3 kg
b. 5.8 x 10–4 kg
d. 2.5 x 10–4 kg
Problems:
1. A 2.0 kg slab of concrete requires 11 kJ to raise its temperature from 23 °C to
29 °C. What is the specific heat of the concrete? (Caution: units)
11000 / [2.0*(29-23)] = 917J
2. A sample of 0.0400 kg of iron at 30 °C is placed in a container of 0.500 kg of water at
17 °C. The specific heat of iron is 450 J/kg • °C and the specific heat of water is 4180
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J/kg • °C. What is the final temperature of the system when it reaches thermal
equilibrium?
.04*450(Tf-30) + 0.5*4186(Tf-17) = 0;
Solve for Tf; 18Tf-540 + 2093 Tf -35581 = 0;
2111Tf = 36121; Tf = 17.11 oC
3. Iron has a heat of fusion of 2.66 x 106 J/kg. How much heat must be removed from
7.94 kg of molten iron at its freezing point to turn it into solid iron at the same
temperature?
7.94*2.66 x 106 = 21120400J
4. Ice has a specific heat of 2090 J/kg • K and a heat of fusion of 3.33 x 105 J/kg.
A) How much heat must be added to melt 2.0 kg of ice at 0.0 ° C
2.0*3.33 x 105 = 6.66 x 105J
B) How much heat must be added to raise the temperature from 0.0 ° to 30 °C?
2.0*4186*(30-0) = 251160J
C) What total amount of heat was needed to melt the ice and raise its temperature?
6.66 x 105J + 251160J = 917160J
5. How much heat is required to change 500 g of ice at -50 °C to steam at 115 °C? (Hint:
Refer to the diagram depicting temperature and phase change)
0.5*2090*(0--50) + 0.5*3.33 x 105 + 0.5*4186*(100-0) + 0.5*2.26 x 106 +
0.5*2010*(115-100) = 1573125J
6. If 10 J of energy is added to a system that does 5 J of external work. By how much
will the internal energy increase?
DU = Q – W; DU = 10J – 5J; DU = 5J
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