Question 1

A constriction in a pipe reduces its diameter from 4.0 cm to 2.0 cm. Where the pipe is narrow the water speed is 8.0 m/s. Where it is wide the water speed is:

Accepted Answer

A)  2.0 m/s 
B)  4.0 m/s 
C)  8.0 m/s 
D)  16 m/s 
E)  32 m/s 
A)  2.0 m/s 
B)  4.0 m/s 
C)  8.0 m/s 
D)  16 m/s 
E)  32 m/s

Question 2

The two arms of a U-tube are not identical, one having twice the diameter of the other. A cork in the narrow arm requires a force of 16 N to remove it. The tube is filled with water and the wide arm is fitted with a piston. The minimum force that must be applied to the piston to push the cork out is:

Accepted Answer

A)  4 N 
B)  8 N 
C)  16 N 
D)  32 N 
E)  64 N 
A)  4 N 
B)  8 N 
C)  16 N 
D)  32 N 
E)  64 N

Question 3

If p is a pressure and$\rho$ is a mass density then p/$\rho$ has units of:

Accepted Answer

A)  m2 
B)  m2/s2 
C)  N/m2 
D)  kg/m2 
E)  m3/kg 
A)  m2 
B)  m2/s2 
C)  N/m2 
D)  kg/m2 
E)  m3/kg

Question 4

A 0.50 N metal sinker appears (as measured using a spring scale) to have a mass of 0.45 N when submerged in water. The specific gravity of the metal is:

Accepted Answer

A)  6 
B)  8 
C)  9 
D)  10 
E)  12 
A)  6 
B)  8 
C)  9 
D)  10 
E)  12

Question 5

Water (density = 1.0 * 103 kg/m3) flows downhill through a pipe of diameter 1.5 cm. Its speed at the top of the hill is 7.2 m/s. If the hill is 9.5 m high, what is the gravitational potential energy density of the water at the top of the hill relative to the bottom?

Accepted Answer

A)  cannot be calculated without knowing the pressure 
B)  120 J/m3 
C)  7.2 x 103 J/m3 
D)  9.5 x 103 J/m3 
E)  9.3 x 104 J/m3 
A)  cannot be calculated without knowing the pressure 
B)  120 J/m3 
C)  7.2 x 103 J/m3 
D)  9.5 x 103 J/m3 
E)  9.3 x 104 J/m3

Question 6

"An object completely submerged in a fluid displaces its own volume of fluid." This is:

Accepted Answer

A)  Pascal's paradox 
B)  Archimedes' principle 
C)  Pascal's principle 
D)  true, but none of the above 
E)  false 
A)  Pascal's paradox 
B)  Archimedes' principle 
C)  Pascal's principle 
D)  true, but none of the above 
E)  false

Question 7

A boat floating in fresh water displaces 16,000 N of water. How many newtons of salt water would it displace if it floats in salt water of specific gravity 1.10?

Accepted Answer

A)  12,800 N 
B)  14,400 N 
C)  16,000 N 
D)  17,600 N 
E)  19,200 N 
A)  12,800 N 
B)  14,400 N 
C)  16,000 N 
D)  17,600 N 
E)  19,200 N

Question 8

A lawn sprinkler is made of a 1.0 cm diameter garden hose with one end closed and 25 holes, each with a diameter of 0.050 cm, cut near the closed end. If water flows at 2.0 m/s in the hose, the speed of the water leaving a hole is:

Accepted Answer

A)  2.0 m/s 
B)  32 m/s 
C)  40 m/s 
D)  600 m/s 
E)  800 m/s 
A)  2.0 m/s 
B)  32 m/s 
C)  40 m/s 
D)  600 m/s 
E)  800 m/s

Question 9

The dimensions of a wooden raft (density = 150 kg/m3) are 3.0 m * 3.0 m * 1.0 m. What maximum load can it carry in sea water (density =1020 kg/m3)?

Accepted Answer

A)  1350 kg 
B)  7800 kg 
C)  9200 kg 
D)  19,500 kg 
E)  24,300 kg 
A)  1350 kg 
B)  7800 kg 
C)  9200 kg 
D)  19,500 kg 
E)  24,300 kg

Question 10

Which of the following statements about Pascal's principle is true?

Accepted Answer

A)  It is valid only for incompressible fluids 
B)  It explains why light objects float 
C)  It explains why the pressure is greater at the bottom of a lake than at the surface 
D)  It is valid only for objects that are less dense than water 
E)  None of the above is true 
A)  It is valid only for incompressible fluids 
B)  It explains why light objects float 
C)  It explains why the pressure is greater at the bottom of a lake than at the surface 
D)  It is valid only for objects that are less dense than water 
E)  None of the above is true

Question 11

A blast of wind tips a sailboat in the clockwise direction when viewed from the stern. When the wind ceases the boat rotates back toward the upright position if, when it is tilted, the center of buoyancy:

Accepted Answer

A)  is above the center of gravity 
B)  is below the center of gravity 
C)  is to the right of the center of gravity 
D)  is to the left of the center of gravity 
E)  coincides with the center of gravity 
A)  is above the center of gravity 
B)  is below the center of gravity 
C)  is to the right of the center of gravity 
D)  is to the left of the center of gravity 
E)  coincides with the center of gravity

Question 12

The vessels shown below all contain water to the same height. Rank them according to the pressure exerted by the water on the vessel bottoms, least to greatest.

Accepted Answer

A)  1, 2, 3, 4 
B)  3, 4, 2, 1 
C)  1, 2, 4, 3 
D)  2, 3, 4, 1 
E)  All pressures are the same 
A)  1, 2, 3, 4 
B)  3, 4, 2, 1 
C)  1, 2, 4, 3 
D)  2, 3, 4, 1 
E)  All pressures are the same

Question 13

A fluid of density 9.1 *102 kg/m3 is flowing through a tube at a speed of 5.3 m/s. What is the kinetic energy density of the fluid?

Accepted Answer

A)  cannot be calculated without knowing the pressure 
B)  cannot be calculated without knowing the elevation 
C)  4.8 *103 J/m3 
D)  1.3 *104 J/m3 
E)  2.5* 106 J/m3 
A)  cannot be calculated without knowing the pressure 
B)  cannot be calculated without knowing the elevation 
C)  4.8 *103 J/m3 
D)  1.3 *104 J/m3 
E)  2.5* 106 J/m3

Question 14

A tin can has a volume of 1000 cm3 and a mass of 100 g. Approximately what mass of lead shot can it carry without sinking in water?

Accepted Answer

A)  900 g 
B)  100 g 
C)  1000 g 
D)  1100 g 
E)  980 g 
A)  900 g 
B)  100 g 
C)  1000 g 
D)  1100 g 
E)  980 g

Question 15

A certain object floats in fluids of density   Which of the following statements is true?

Accepted Answer

A)  the buoyant force of fluid 1 is greater than the buoyant forces of the other two fluids 
B)  the buoyant force of fluid 3 is greater than the buoyant forces of the other two fluids 
C)  the three fluids exert the same buoyant force 
D)  the object displace the same volume of all three fluids 
E)  none of these are true 
A)  the buoyant force of fluid 1 is greater than the buoyant forces of the other two fluids 
B)  the buoyant force of fluid 3 is greater than the buoyant forces of the other two fluids 
C)  the three fluids exert the same buoyant force 
D)  the object displace the same volume of all three fluids 
E)  none of these are true

Question 16

A hydraulic press has one piston of diameter 2.0 cm and the other piston of diameter 8.0 cm. What force must be applied to the smaller piston to obtain a force of 1600 N at the larger piston:

Accepted Answer

A)  100 N 
B)  400 N 
C)  1600 N 
D)  6400 N 
E)  26000 N 
A)  100 N 
B)  400 N 
C)  1600 N 
D)  6400 N 
E)  26000 N

Question 17

A solid has a volume of 8 cm3. When weighed on a spring scale calibrated in grams, the scale indicates 20 g. What does the scale indicate if the object is weighed while immersed in a liquid of density 2 g/cm3?

Accepted Answer

A)  4 g 
B)  10 g 
C)  12 g 
D)  16 g 
E)  zero, since the object will float 
A)  4 g 
B)  10 g 
C)  12 g 
D)  16 g 
E)  zero, since the object will float

Question 18

A non-viscous incompressible fluid is pumped steadily into the narrow end of a long tapered pipe and emerges from the wide end. The pressure at the input is greater than at the output. A possible explanation is:

Accepted Answer

A)  the fluid speed increases from input to output 
B)  the fluid speed is the same at the two ends 
C)  the fluid is flowing uphill 
D)  the fluid is flowing downhill 
E)  the fluid is flowing horizontally 
A)  the fluid speed increases from input to output 
B)  the fluid speed is the same at the two ends 
C)  the fluid is flowing uphill 
D)  the fluid is flowing downhill 
E)  the fluid is flowing horizontally

Question 19

An object hangs from a spring balance. The balance indicates 30 N in air, 20 N when the object is submerged in water. What does the balance indicate when the object is submerged in liquid with a density that is half of water?

Accepted Answer

A)  20 N 
B)  25 N 
C)  30 N 
D)  35 N 
E)  40 N 
A)  20 N 
B)  25 N 
C)  30 N 
D)  35 N 
E)  40 N

Question 20

To measure moderately low pressures oil with a density of 8.5 * 102 kg/m3 is used in place of mercury in a barometer. A change in the oil column of 1.0 mm indicates a change in pressure of about:

Accepted Answer

A)  1.2 *10-7 Pa 
B)  1.2 *10-5 Pa 
C)  0.85 Pa 
D)  1.2 Pa 
E)  8.3 Pa 
A)  1.2 *10-7 Pa 
B)  1.2 *10-5 Pa 
C)  0.85 Pa 
D)  1.2 Pa 
E)  8.3 Pa

Exam 14: Fluids

A constriction in a pipe reduces its diameter from 4.0 cm to 2.0 cm. Where the pipe is narrow the water speed is 8.0 m/s. Where it is wide the water speed is:

If p is a pressure and ρ\rhoρ is a mass density then p/ ρ\rhoρ has units of:

A 0.50 N metal sinker appears (as measured using a spring scale) to have a mass of 0.45 N when submerged in water. The specific gravity of the metal is:

Water (density = 1.0 * 103 kg/m3) flows downhill through a pipe of diameter 1.5 cm. Its speed at the top of the hill is 7.2 m/s. If the hill is 9.5 m high, what is the gravitational potential energy density of the water at the top of the hill relative to the bottom?

"An object completely submerged in a fluid displaces its own volume of fluid." This is:

A boat floating in fresh water displaces 16,000 N of water. How many newtons of salt water would it displace if it floats in salt water of specific gravity 1.10?

A lawn sprinkler is made of a 1.0 cm diameter garden hose with one end closed and 25 holes, each with a diameter of 0.050 cm, cut near the closed end. If water flows at 2.0 m/s in the hose, the speed of the water leaving a hole is:

The dimensions of a wooden raft (density = 150 kg/m3) are 3.0 m * 3.0 m * 1.0 m. What maximum load can it carry in sea water (density =1020 kg/m3)?

Which of the following statements about Pascal's principle is true?

A blast of wind tips a sailboat in the clockwise direction when viewed from the stern. When the wind ceases the boat rotates back toward the upright position if, when it is tilted, the center of buoyancy:

The vessels shown below all contain water to the same height. Rank them according to the pressure exerted by the water on the vessel bottoms, least to greatest.

A fluid of density 9.1 *102 kg/m3 is flowing through a tube at a speed of 5.3 m/s. What is the kinetic energy density of the fluid?

A tin can has a volume of 1000 cm3 and a mass of 100 g. Approximately what mass of lead shot can it carry without sinking in water?

A certain object floats in fluids of density Which of the following statements is true?

A hydraulic press has one piston of diameter 2.0 cm and the other piston of diameter 8.0 cm. What force must be applied to the smaller piston to obtain a force of 1600 N at the larger piston:

A solid has a volume of 8 cm3. When weighed on a spring scale calibrated in grams, the scale indicates 20 g. What does the scale indicate if the object is weighed while immersed in a liquid of density 2 g/cm3?

A non-viscous incompressible fluid is pumped steadily into the narrow end of a long tapered pipe and emerges from the wide end. The pressure at the input is greater than at the output. A possible explanation is:

An object hangs from a spring balance. The balance indicates 30 N in air, 20 N when the object is submerged in water. What does the balance indicate when the object is submerged in liquid with a density that is half of water?

To measure moderately low pressures oil with a density of 8.5 * 102 kg/m3 is used in place of mercury in a barometer. A change in the oil column of 1.0 mm indicates a change in pressure of about:

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

If p is a pressure and $\rho$ is a mass density then p/ $\rho$ has units of:

Water (density = 1.0 * 10³ kg/m³) flows downhill through a pipe of diameter 1.5 cm. Its speed at the top of the hill is 7.2 m/s. If the hill is 9.5 m high, what is the gravitational potential energy density of the water at the top of the hill relative to the bottom?

The dimensions of a wooden raft (density = 150 kg/m³) are 3.0 m * 3.0 m * 1.0 m. What maximum load can it carry in sea water (density =1020 kg/m³)?

A fluid of density 9.1 *10² kg/m³ is flowing through a tube at a speed of 5.3 m/s. What is the kinetic energy density of the fluid?

A tin can has a volume of 1000 cm³ and a mass of 100 g. Approximately what mass of lead shot can it carry without sinking in water?

A solid has a volume of 8 cm³. When weighed on a spring scale calibrated in grams, the scale indicates 20 g. What does the scale indicate if the object is weighed while immersed in a liquid of density 2 g/cm³?

To measure moderately low pressures oil with a density of 8.5 * 10² kg/m³ is used in place of mercury in a barometer. A change in the oil column of 1.0 mm indicates a change in pressure of about: