Transcript BR. HMWK 2012-03-07 11052

Thermodynamics and Fluids
Review
Multiple Choice
• Answer the five multiple choice questions
with your group
• Give a confidence rating to each question
– 5 indicates that you are most confident
– 1 indicates that you are least confident
• Your confidence rating determines the
number of points you will receive for a
correct answer
1. A fluid flows steadily from left to right in the
pipe shown above. The diameter of the pipe is
less at point 2 than at point 1, and the fluid
density is constant throughout the pipe. How
do the velocity of flow and the pressure at
points 1 and 2 compare?
a.
b.
c.
d.
e.
v1 < v2
v1 < v2
v1 = v2
v1 > v2
v1 > v2
P1 = P2
P1 > P2
P1 < P2
P1 = P2
P1 > P2
2. Each of the beakers above is filled to the same
depth h with a liquid of density ρ. The area A of
the flat bottom is the same for each beaker.
Which of the following ranks the beakers
according to the net downward force exerted by
the liquid on the flat bottom, from greatest force
to least force.
a.
b.
c.
d.
e.
I, III, II, IV
I, IV, III, II
II, III, IV, I
IV, III, I, II
None of the above; the force on each is the same.
3. A spring scale calibrate in kg is used to
determine the density of a rock specimen. The
reading on the spring scale is 0.45 kg when
the specimen is suspended in air and 0.36 kg
when the specimen is fully submerged in
water. If the density of water is 1000 kg/m3,
the density of the rock specimen is…
a.
b.
c.
d.
e.
2.0 × 102 kg/m3
8.0 × 102 kg/m3
1.25 × 103 kg/m3
4.0 × 103 kg/m3
5.0 × 103 kg/m3
A certain quantity of an ideal gas initially at
temperature T0, pressure p0, and volume V0 is
compressed to one half its initial volume. As shown
above, the process may be adiabatic (process 1),
isothermal (process 2), or isobaric (process 3).
4.
Which of the following is true of the mechanical work
done on the gas?
a.
b.
c.
d.
e.
It is greatest for process 1.
It is greatest for process 3.
It is the same from processes 1 and 2 and less for process 3.
It is the same for processes 2 and 3 and less for process 1.
It is the same for all three processes.
A certain quantity of an ideal gas initially at
temperature T0, pressure p0, and volume V0 is
compressed to one half its initial volume. As shown
above, the process may be adiabatic (process 1),
isothermal (process 2), or isobaric (process 3).
5.
Which of the following is true of the final temperature
of this gas?
a.
b.
c.
d.
e.
It is greatest for process 1.
It is greatest for process 2.
It is greatest for process 3.
It is the same for processes 1 and 2.
It is the same for processes 1 and 3.
Round 2
1. A monatomic ideal gas undergoes an
adiabatic expansion. During this
process, the temperature of the gas…
a.
b.
c.
d.
e.
Remains constant
Increases.
Decreases.
Increases, then decreases.
Decreases, then increases.
2.
Two samples of a monatomic ideal gas are being kept
at the same temperature and pressure in different
containers. Container A has twice the volume of
container B. What can you say about the internal
energy of container A compared to container B?
a.
b.
The internal energy of both containers is identical.
The internal energy of container A is half the internal
energy of container B.
The internal energy of container A is twice the internal
energy of container B.
The internal energy of container A is more than twice
the internal energy of container B.
The internal energy of container A is less than half the
internal energy of container B.
c.
d.
e.
3. A metal bar has a coefficient of linear
expansion of 5 × 10-6 (ºC)-1. If the bar is
originally 1.0 m long at 20ºC, how much
longer would is it at 120ºC?
a.
b.
c.
d.
e.
1.0005 m
19 × 10-4 m
5 × 10-6 m
0.5 mm
2.0 mm
4. A sample of 10 moles of an ideal gas is
originally at a pressure of 300 kPa. It
undergoes an isothermal compression from an
original volume of 1.2 m3 to a final volume of
0.4 m3. The final pressure is most nearly…
a.
b.
c.
d.
e.
100 kPa
600 kPa
90 kPa
9000 kPa
900 kPa
5. Through a series of thermodynamic processes,
the internal energy of a sample of confined gas
is increased by 560 J. If the net amount of
work done on the sample by its surroundings is
320 J, how much heat was transferred
between the gas and its environment?
a.
b.
c.
d.
e.
240 J absorbed
240 J dissipated
880 J absorbed
880 J dissipated
None of the above