Download Exam 4 - Nicholls State University

Name: ________________________ Class: ___________________ Date: __________
ID: A
Exam 4 -- PHYS 101
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
____
____
____
____
____
____
1. A steel tape measure is marked such that it gives accurate measurements at room temperature. You place the
tape measure in a very cold place and measure the length of a bar which you know to be 1 meter in length.
What length will the cold tape measure show?
a. length = 1 meter
c. length > 1 meter
b. length < 1 meter
d. Not enough information
2. You want to take apart a couple of steel parts held together by brass screws, but the parts are stuck. What
should you do to remove the screws? (The coefficient of linear expansion for steel is 11 ×10-6 °C-1. The
coefficient for brass is 19×10-6 °C-1.)
a. heat the parts
c. Not enough information given
b. cool the parts
3. Which of these is the Kelvin temperature scale not based upon?
a. freezing point of water
d. temperature of the cosmic background
b. heat of vaporization of water
e. all of the above
c. boiling point of water
4. Which is the smallest unit of temperature: one degree Kelvin, Celsius, or Fahrenheit?
a. Celsius
c. Kelvin & Celsius
b. Kelvin
d. Fahrenheit
5. You heat a bimetallic strip that is made of brass on one side and steel on the other side. As you heat it, the
strip will bend towards which side? (The coefficient of linear expansion for steel is 11 ×10-6 °C-1. The
coefficient for brass is 19×10-6 °C-1.)
a. the brass side
c. the strip will not bend
b. the steel side
d. don’t know
6. An atomic ideal gas occupies a volume of 0.01 m 3 at 30°C and a pressure of 1×105 Pa. How many atoms are
present in the gas? (universal gas constant=8.314 J/(mol K); Boltzmann’s constant = 1.38 ×10-23 J/K;
Avogadro’s number is 6.02×1023)
a. 4.0 moles
c. 0.4 atoms
b. 2.4×1024 atoms
d. 2.4×1023 atoms
7. A containter of atomic gas is present in a volume of 0.02 m 3, with a temperature of 20°C, and at a pressure of
1 atmosphere. If the pressure drops to 1×10-5 atmosphere, what is the temperature? (ideal gas constant =
8.314 J/mol K; 1 atm =1×105 Pa)
a.
b.
0°C
2×10-4 K
c.
d.
1
2.7 K
3 mK
Name: ________________________
ID: A
____
8. Two identical cylinders at the same temperature contain the same gas. If container A has 4 times as much
gas as container B, which has the highest pressure?
a. A
c. they have the same pressure
b. B
d. not enough information given
____ 9. Neon has a molar mass of 0.0202 kg/mol. Helium has a molar mass of 0.004 kg/mol. In one mole, which has
the greater number of atoms?
a. Neon
c. both the same
b. Helium
____ 10. A steel bar is 10 meters long. It is heated from 100°C to 1000°C. What is the new length of the steel bar?
(The coefficient of linear expansion for steel is 11 ×10-6 °C-1.) For this problem, ignore the proper use of
significant figures.
a. 10.001 m
c. 10 cm
b. 10.1 m
d. 0.1 m
____ 11. The specific heat of aluminum is 900 J/kg °C. The specific heat of glass is 837 J/kg °C. If two pieces of
glass and aluminum, each with the same mass, are placed in an oven. For which of these will the temperature
rise more quickly?
a. aluminum
c. temperature of both will increase at same
rate
b. glass
d. not enough information given
____ 12. Water falls from 50 meters. Assume all gravitational potential energy is converted to thermal energy. What
is the change in temperature of the water? The specific heat of water is 4186 J/kg °C.
c. 1°C
a. 0.1°C
d. not enough information given
b. 0.01°C
____ 13. You place a mass of copper at -10 °C into a container with 100 g of steam at 100 °C. The system reaches an
equilibrium temperature of 45°C. What is the mass of the copper? (for water: latent heat of
vaporization=2.26×106 J/kg, latent heat of fusion=3.33×105 J/kg, and specific heat=4186 J/kg°C. For copper,
the specific heat is 387 J/kg°C.)
a. 10 kg
c. 1 kg
b. 3 kg
d. 10,000 kg
____ 14. Does one transer heat into a substance (Q>0) or take heat away from a substance (Q<0) in order to convert it
from a vapor to a liquid?
a. Q<0
c. not enough information
b. Q>0
d. neither, Q=0
2
Name: ________________________
ID: A
____ 15. Convection is the transfer of heat caused by
a. contact between two objects
c. the conversion of work to heat
b. the transfer of radiation
d. the motion of a substance
____ 16. Water has a higher specific heat than sand. Therefore, in the afternoon, breezes blow
a. from the beach to the ocean
c. either way, makes no difference
b. from the ocean to the beach
____ 17. You put 1 kg of ice at 0°C with 1 kg of water at 50°C. What is the final temperature of the water? (For
water: latent heat of vaporization=2.26×106 J/kg, latent heat of fusion=3.33×105 J/kg, and specific
heat=4186 J/kg°C.)
c. 0°C
a. 25°C
b. 75°C
d. 50°C
____ 18. A special type of star has a temperature of 100,000 K and a radius of 10 3 m. The star is a perfect blackbody
absorber. What power is radiated by the star in the form of radiation? (The Stefan-Boltzmann constant is
5.67×10-8 W/m2K4)
a. 7×1019 W
c. 0 W
b. 6 W
d. 70,000 W
____ 19. How much heat is required to raise the temperature of 100 g of ice from -20°C to 50°C? (For water: latent
heat of vaporization=2.26×106 J/kg, latent heat of fusion=3.33×105 J/kg, and specific heat=4186 J/kg°C.)
c. 2×105 J
a. 5×104 J
7
d. 6×104 J
b. 6×10 J
____ 20. Zero degrees Celsius is equivalent to which of these temperatures:
a. 273 K
c. -273 K
b. 20°F
d. -32°F
____ 21. In which of these processes is the internal energy of the gas equal to the work done on the gas?
a. adiabatic
d. isovolumetric
b. isothermal
e. isochroic
c. isobaric
3
Name: ________________________
ID: A
____ 22. In this figure, what is the work done on the gas when it follows the path ab (beginning at a and ending at b)?
a. -6000
c. -12,000 J
b. 12,000 J
d. -10,000 J
____ 23. In the figure for problem 22, what is the heat transferred to the gas for the cyclic path ABCA?
a. 6,000 J
c. -6,000 J
b. 12,000 J
d. 6 J
____ 24. In a heat engine, 10,000 J of heat is absorbed by the steam from the coal boiler. This steam powers a turbine
with 8,000 J of work. Then, 2,000 J of heat is dispersed in a cooling tower.
What is the efficiency of this heat engine?
a. 20%
c. 80%
b. 160%
d. 25%
____ 25. Which of these is not a step in the 4-stroke internal combustion engine?
a. power
c. exhaust
b. ignition
d. intake
____ 26. The second law of thermodynamics says which of these can never be zero?
a. entropy
c. work
b. heat from the hot reservoir
d. heat to the cold reservoir
4
Name: ________________________
ID: A
____ 27. A movable piston has a mass of 8.00 kg and an area of 9.50 cm 2. Inside the piston, 0.1 moles of an ideal gas
experience a temperature change from 30°C to 100°C while the piston moves (without friction). How much
work is done on the gas? (universal gas constant=8.314 J/(mol K); Boltzmann’s constant = 1.38 ×10-23 J/K;
Stefan-Boltzmann constant=5.67×10-8 W/(m2K4))
c. 2×10-22 J
a. 4×10-7 J
b. 60 J
d. -60 J
____ 28. Gas in a container is at a pressure of 1000 Pa and a volume of 4 m 3. How much work is done on the gas if it
expands at constant pressure to three times its original volume?
a. 8,000 J
c. -8,000 J
b. -12,000 J
d. 4,000 J
____ 29. An ideal, monatomic gas undergoes a thermal process where no heat is transferred to the gas. The inital
pressure is 1000 Pa, and the initial volume is 0.1 m 3. The final volume is 0.2 m3. What is the final pressure?
5
3
(For a monatomic gas, Cp = R and Cv = R.)
2
2
a. 300 Pa
c. 700 Pa
b. 100 Pa
d. 500 Pa
____ 30. You are using version “A” of this test. Please bubble “A” and write “Version A” on your scantron.
a. A
c. C
b. B
d. D
5
ID: A
Exam 4 -- PHYS 101
Answer Section
MULTIPLE CHOICE
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.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
C
B
E
D
B
D
D
A
C
B
B
A
A
A
D
B
C
C
D
A
A
D
A
C
B
D
D
C
A
A
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1