Question 1

When you blow some air above the upper face of a paper strip, the paper rises. This occurs because

Accepted Answer

A)  the air above the upper face of the paper moves faster, which makes the pressure higher than at the lower face. 
B)  the air above the upper face of the paper moves faster, which makes the pressure lower than at the lower face. 
C)  the air above the upper face of the paper moves faster but the pressure remains constant. 
D)  the air above the upper face of the paper moves slower, which makes the pressure higher than at the lower face. 
E)  the air above the upper face of the paper moves slower, which makes the pressure lower than at the lower face. 
A)  the air above the upper face of the paper moves faster, which makes the pressure higher than at the lower face. 
B)  the air above the upper face of the paper moves faster, which makes the pressure lower than at the lower face. 
C)  the air above the upper face of the paper moves faster but the pressure remains constant. 
D)  the air above the upper face of the paper moves slower, which makes the pressure higher than at the lower face. 
E)  the air above the upper face of the paper moves slower, which makes the pressure lower than at the lower face.

Question 2

A rock is under water in a shallow lake. As the rock sinks deeper and deeper into water, the buoyant force on it

Accepted Answer

A)  increases. 
B)  decreases. 
C)  remains constant. 
A)  increases. 
B)  decreases. 
C)  remains constant.

Question 3

Water flows in the horizontal pipe shown in the figure. At A the diameter is 5.00 cm and at B the diameter is 4.00 cm The fluid in the manometer is mercury, which has a density of 13,600 kg/m3. The manometer reading h is 4.40 cm. We can treat water as an ideal fluid having a density of 1000 kg/m3. What volume of water is flowing through the pipe per second?

Accepted Answer

A)  0.0206 m3/s 
B)  0.0426 m3/s 
C)  0.00560 m3/s 
D)  0.372 m3/s 
E)  0.186 m3/s 
A)  0.0206 m3/s 
B)  0.0426 m3/s 
C)  0.00560 m3/s 
D)  0.372 m3/s 
E)  0.186 m3/s

Question 4

A 1000-kg object hangs from the lower end of a steel rod 5.0 m long that is suspended vertically. The diameter of the rod is 0.80 cm and Young's modulus for the rod is 210,000 MN/m2. What is the elongation of the rod due to this object?

Accepted Answer

A)  1.2 cm 
B)  0.46 cm 
C)  0.12 cm 
D)  1.8 cm 
E)  0.047 cm 
A)  1.2 cm 
B)  0.46 cm 
C)  0.12 cm 
D)  1.8 cm 
E)  0.047 cm

Question 5

A horizontal tube consists of a 7.0-cm diameter pipe that narrows to a 2.0-cm-diameter throat. In the pipe, the water pressure is twice atmospheric pressure and the water flows with a speed of 0.40 m/s. What is the pressure in the throat, assuming that the water behaves like an ideal fluid? The density of water is 1000 kg/m3, and atmospheric pressure is 1.01 × 105 Pa.

Accepted Answer

A)  1.9 atm 
B)  0.12 atm 
C)  2.1 atm 
D)  2.0 atm 
A)  1.9 atm 
B)  0.12 atm 
C)  2.1 atm 
D)  2.0 atm

Question 6

A level pipe contains a nonviscous, incompressible fluid with a density 1200 kg/m3 that is flowing steadily. At one position within the pipe, the pressure is 300 kPa and the speed of the flow is 20.0 m/s. At another position, the pressure is 200 kPa. What is the speed of the flow at this second position?

Accepted Answer

A)  567 m/s 
B)  16.2 m/s 
C)  32.9 m/s 
D)  23.8 m/s 
E)  186 m/s 
A)  567 m/s 
B)  16.2 m/s 
C)  32.9 m/s 
D)  23.8 m/s 
E)  186 m/s

Question 7

Tensile train is

Accepted Answer

A)  the ratio of the change in length to the original length. 
B)  the stress per unit area. 
C)  the same as force. 
D)  the applied force per cross-sectional area. 
E)  the ratio of stress to elastic modulus. 
A)  the ratio of the change in length to the original length. 
B)  the stress per unit area. 
C)  the same as force. 
D)  the applied force per cross-sectional area. 
E)  the ratio of stress to elastic modulus.

Question 8

Water flows through a pipe having a varying width. More water flows per second through the wide section than through the narrow section because there is more room for it to flow.

Accepted Answer

A) True 
 B)False

Question 9

The graph in the figure shows the force on an object as a function of the elongation caused by that force. Which statement about this object is true?

Accepted Answer

A)  The object obeys Hooke's law at all points from A to C. 
B)  The object obeys Hooke's law at all points from B to C. 
C)  The object obeys Hooke's law at all points from A to B. 
D)  The elastic limit occurs at point C. 
E)  The region of elastic behavior occurs from B to C. 
A)  The object obeys Hooke's law at all points from A to C. 
B)  The object obeys Hooke's law at all points from B to C. 
C)  The object obeys Hooke's law at all points from A to B. 
D)  The elastic limit occurs at point C. 
E)  The region of elastic behavior occurs from B to C.

Question 10

A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub?

Accepted Answer

A)  It goes up. 
B)  It goes down. 
C)  It does not change. 
D)  This cannot be determined without knowing the volume of the top piece of wood. 
A)  It goes up. 
B)  It goes down. 
C)  It does not change. 
D)  This cannot be determined without knowing the volume of the top piece of wood.

Question 11

A copper sphere has a radius of 2.50 m under normal room pressure of 1.0 × 105 N/m2. If we increase the pressure on this sphere to 10 times the normal room pressure, what is the change in its volume? The bulk modulus for copper is 1.4 × 1011 Pa.

Accepted Answer

Question 12

One of the dangers of tornados and hurricanes is the rapid drop in air pressure that is associated with such storms. Assume that the air pressure inside of a sealed house is 1.02 atm when a hurricane hits. The hurricane rapidly decreases the external air pressure to 0.910 atm. A square window in an outside wall of the house measures 2.02 m on each side. What net force (directed outwards) is exerted on this window? (1 atm = 1.01 × 105 Pa.)

Accepted Answer

A)  4.53 × 104 N 
B)  5.14 × 104 N 
C)  4.78 × 105 N 
D)  5.37 × 105 N 
A)  4.53 × 104 N 
B)  5.14 × 104 N 
C)  4.78 × 105 N 
D)  5.37 × 105 N

Exam 15: Fluids and Elasticity

When you blow some air above the upper face of a paper strip, the paper rises. This occurs because

A rock is under water in a shallow lake. As the rock sinks deeper and deeper into water, the buoyant force on it

A 1000-kg object hangs from the lower end of a steel rod 5.0 m long that is suspended vertically. The diameter of the rod is 0.80 cm and Young's modulus for the rod is 210,000 MN/m2. What is the elongation of the rod due to this object?

Tensile train is

Water flows through a pipe having a varying width. More water flows per second through the wide section than through the narrow section because there is more room for it to flow.

The graph in the figure shows the force on an object as a function of the elongation caused by that force. Which statement about this object is true?

A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub?

A copper sphere has a radius of 2.50 m under normal room pressure of 1.0 × 105 N/m2. If we increase the pressure on this sphere to 10 times the normal room pressure, what is the change in its volume? The bulk modulus for copper is 1.4 × 1011 Pa.

Concepts of Motion

Kinematics in One Dimension

Vectors and Coordinate Systems

Kinematics in Two Dimensions

Force and Motion

Dynamics I: Motion Along a Line

Newtons Third Law

Dynamics Ii: Motion in a Plane

Impulse and Momentum

Energy

Work

Rotation of a Rigid Body

Newtons Theory of Gravity

Oscillations

A Macroscopic Description of Matter

Work, Heat, and the First Law of Thermodynamics

The Micromacro Connection

Heat Engines and Refrigerators

Traveling Waves

Superpositions

Wave Optics

Ray Optics

Optical Instruments

Electric Charges and Forces

The Electric Field

Gausss Law

The Electric Potential

Potential and Field

Current and Resistance

Fundamentals of Circuits

The Magnetic Field

Electromagnetic Induction

Electromagnetic Fields and Waves

Ac Circuits

Relativity

The Foundations of Modern Physics

Quantization

Wave Functions and Uncertainty

One-Dimensional Quantum Mechanics

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A 1000-kg object hangs from the lower end of a steel rod 5.0 m long that is suspended vertically. The diameter of the rod is 0.80 cm and Young's modulus for the rod is 210,000 MN/m². What is the elongation of the rod due to this object?

A copper sphere has a radius of 2.50 m under normal room pressure of 1.0 × 10⁵N/m². If we increase the pressure on this sphere to 10 times the normal room pressure, what is the change in its volume? The bulk modulus for copper is 1.4 × 10¹¹ Pa.