Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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Which of the following statements is not correct?
a. | A fluid flows. | b. | A fluid has a definite
shape. | c. | Molecules of a fluid are free to move past each other. | d. | A fluid changes its
shape easily. |
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2.
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If an object is only partially submerged in a fluid, which of the following is
true?
a. | The volume of the displaced fluid equals the volume of the
object. | b. | The density of the fluid equals the density of the object. | c. | The density of the
fluid is greater than the density of the object. | d. | The density of the fluid is less than the
density of the object. |
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3.
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The gauge pressure for the air in a balloon equals 1.01 ´ 10  Pa. If atmospheric pressure is equal to 1.01 ´ 10  Pa, what is the absolute pressure of the air
inside the balloon? a. | 0 Pa | c. | 1.01 ´ 10
Pa | b. | 5.05 ´ 10
Pa | d. | 2.02 ´ 10 Pa |
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4.
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An ideal fluid flows through a pipe made of two sections with diameters of 1 cm
and 3 cm, respectively. By what factor would you have to multiply the velocity of the liquid flowing
through the 1 cm section to obtain the velocity of liquid flowing through the 3 cm section?
a. | 9 | c. |  | b. | 6 | d. |  |
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5.
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If the flow rate of a liquid is measured at 8.0 ´ 10  m  /s going through a 20.0 m radius
pipe, which of the following is the average fluid velocity in the pipe? a. | 4.0 ´ 10
m/s | c. | 2.0 m/s | b. | 0.64 m/s | d. | 6.4 m/s |
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6.
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Consider two steel rods, A and B. B has three times the area and twice the
length of A, so Young's modulus for B will be what factor times Young's modulus for
A?
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7.
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The pressure inside a commercial airliner is maintained at 1.00 atm
(105 Pa). What is the net outward force exerted on a 1.0 m ´ 2.0 m cabin door if the outside pressure is 0.30 atm?
a. | 140 N | b. | 1 400 N | c. | 14 000
N | d. | 140 000 N |
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8.
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What is the total force on the bottom of a 2.0-m-diameter by 1.0-m-deep round
wading pool due to the weight of the air and the weight of the water? (Note the pressure contribution
from the atmosphere is 1.0 ´ 105 N/m2, the
density of water is 1 000 kg/m3, and g = 9.8 m/s2.)
a. | 3.4 ´ 105 N | b. | 2.4 ´ 106 N | c. | 3.2 ´
106 N | d. | 6.0 ´ 106
N |
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9.
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A piece of aluminum has density 2.70 g/cm3 and mass 775 g. The
aluminum is submerged in a container of oil of density 0.650 g/cm3. A spring balance is
attached with string to the piece of aluminum. What reading will the balance register in grams (g)
for the submerged metal?
a. | 960 g | b. | 775 g | c. | 588
g | d. | 190 g |
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10.
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A heavily loaded boat is floating in a pond. The boat sinks because of a leak.
What happens to the surface level of the pond?
a. | It stays the same. | b. | It goes up. | c. | It goes
down. | d. | More information is needed to reach a conclusion. |
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11.
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The flow rate of blood through the average human aorta, of radius 1.0 cm, is
about 90 cm3/s. What is the speed of the blood flow through the aorta?
a. | 14 cm/s | b. | 32 cm/s | c. | 37
cm/s | d. | 29 cm/s |
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12.
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The Garfield Thomas water tunnel at Pennsylvania State University has a circular
cross-section that constricts from a diameter of 3.6 m to the test section, which is 1.2 m in
diameter. If the speed of flow is 3.0 m/s in the large-diameter pipe, determine the speed of flow in
the test section.
a. | 9.0 m/s | b. | 18 m/s | c. | 27
m/s | d. | 1.0 m/s |
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13.
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It takes 2.0 minutes to fill a gas tank with 40 liters of gasoline. If the pump
nozzle is 1.0 cm in radius, what is the average speed of the gasoline as it leaves the nozzle? (1 000
liters = one cubic meter)
a. | 0.27 m/s | b. | 1.1 m/s | c. | 11
m/s | d. | 64 m/s |
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14.
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A container is filled with water and the pressure at the container bottom is
P. If the container is instead filled with oil having specific gravity 0.80, what new bottom
pressure results?
a. | a pressure < P | b. | the same pressure P | c. | a pressure >
P | d. | This is unable to be determined with the information
given. |
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15.
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Pressure is
a. | proportional to both force and
area. | b. | proportional to force and inversely proportional to
area. | c. | inversely proportional to force and proportional to
area. | d. | inversely proportional to both force and
area. | e. | proportional only to
area. |
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16.
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A flask of water rests on a scale. If you dip your
finger into the water, without touching the flask, the reading on the scale will
a. | decrease. | c. | increase. | b. | stay the
same. | d. | behave unpredictably. |
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17.
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Salt water has greater density than fresh
water. A boat floats in both fresh water and in salt water. Where is the buoyant force
greater on the boat?
a. | salt water | b. | fresh water | c. | Buoyant force is
the same in both. | d. | Cannot be
determined from the information given. |
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18.
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Water flows through a pipe. The diameter of
the pipe at point B is larger than at point A. Where is the speed of the water
greater?
a. | point A | b. | point B | c. | same at both A and
B | d. | Cannot be determined from the information
given. |
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19.
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The weight of a 1200-kg car is supported equally by
the four tires, which are inflated to the same gauge pressure. What gauge pressure is required so the
area of contact of each tire with the road is 100 cm2?
a. | 11.6 × 105 Pa | c. | 2.9
× 105 Pa | b. | 11.6 × 104
Pa | d. | 2.9 × 104 Pa |
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20.
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Water is flowing in a drainage channel of
rectangular cross-section. At one point, the width of the channel is 12 m, the depth of water is 6.0
m, and the speed of the flow is 2.5 m/s. At a point downstream, the width has narrowed to 9.0 m, and
the depth of water is 8.0 m. What is the speed of the flow at the second point?
a. | 2.0 m/s | b. | 2.5 m/s | c. | 3.0
m/s | d. | 3.5 m/s | e. | 4.0 m/s |
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21.
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An airplane is flying in air with a density of 1.29
kg/m3. A pressure gauge measures the difference in pressure between a point on the nose of the
airplane and a point on the fuselage. The pressure on the nose is higher by 60.0 kPa. What is the
speed of the plane relative to the air?
a. | 295 m/s | b. | 300 m/s | c. | 305
m/s | d. | 310 m/s | e. | 315 m/s |
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True/False
Indicate whether the
statement is true or false.
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22.
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To determine gauge pressure, add the atmospheric
pressure to the absolute pressure.
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23.
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Pressure in a fluid decreases with
depth.
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24.
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The buoyant force acting on an object is equal to
the weight of the object.
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25.
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An object floats on a fluid if its density is less
than that of the fluid.
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