Hour Exam 2 | How Things Work - Fall 2006 | PHYS 140 | Exams Classical Physics

Physics 140 Hour Exam 2 March 14, 2006

FRIDAY, MARCH 17, 2006: PLEASE NOTE CREDIT IS BEING GIVEN FOR

* Problem 15 (Version A) answers B OR D

* Problem 26 (Version A) answers B, C, OR E

THIS WILL BE REFLECTED IN YOUR GRADE, NOT YOUR ON-LINE EXAM

QUESTIONS

Please do not open this exam book until you are told to do so.

You will need

1. A #2 pencil

2. One scantron answer sheet

3. One exam question booklet

On the scantron answer sheet:

1. Use a #2 pencil. Do not use a mechanical pencil or pen. Darken each circle completely, but

stay within the boundary. If you decide to change an answer, erase vigorously: The scanner

sometimes registers incompletely erased marks as intended answers, and this can adversely

affect your grade. Light marks or marks extending outside the circle may be read improperly

by the scanner. Be especially careful that your mark covers the center of its circle.

2. This Exam Booklet is Version A. Mark the A circle in the TEST FORM box near the

middle of your answer sheet. DO THIS NOW! WE WILL ASSESS A 1 POINT (RAW

SCORE) PENALTY FOR FAILURE TO DO THIS.

3. Print YOUR LAST NAME in the designated spaces at the left side of the answer sheet, and

then mark the corresponding circle below each letter. Do the same for your FIRST NAME

INITIAL.

4. Print your NETWORK ID in the designated spaces at the right side of the answer sheet,

starting in the left-most column, and then mark the corresponding circle below each

character. If there is a letter "o" in your NetID, be sure to mark the "o" circle, and not the

circle for the digit zero. If and only if there is a hyphen "-" in your NetID, mark the hyphen

circle at the bottom of the column. When you have finished marking the circles

corresponding to your NetID, check particularly that you have not marked two circles in any

one of the columns.

5. Do not write in or mark the circles in any of the other boxes (STUDENT NUMBER, DATE,

SECTION, SCORES, SPECIAL CODE).

6. Mark only one answer per question.

7. When told to do so: Check to make sure that the test booklet is complete. There are 11

numbered pages, including this cover sheet.

8. If you understand the statement below, please sign (DO NOT PRINT) your name in the

space provided. If you do not understand, please ask the professor for clarification.

Academic Integrity—Giving assistance to or receiving assistance from another student or using

unauthorized materials during a University Examination can be grounds for disciplinary

action, up to and including dismissal from the University

Page 1 of 8 pages

(45 Problems)

Partial preview of the text

Download Hour Exam 2 | How Things Work - Fall 2006 | PHYS 140 and more Exams Classical Physics in PDF only on Docsity!

FRIDAY, MARCH 17, 2006: PLEASE NOTE CREDIT IS BEING GIVEN FOR

* Problem 15 (Version A) answers B OR D

* Problem 26 (Version A) answers B, C, OR E

THIS WILL BE REFLECTED IN YOUR GRADE, NOT YOUR ON-LINE EXAM

QUESTIONS

Please do not open this exam book until you are told to do so.

You will need

1. A #2 pencil

2. One scantron answer sheet

3. One exam question booklet

On the scantron answer sheet:

1. Use a #2 pencil. Do not use a mechanical pencil or pen. Darken each circle completely, but

stay within the boundary. If you decide to change an answer, erase vigorously: The scanner

sometimes registers incompletely erased marks as intended answers, and this can adversely

affect your grade. Light marks or marks extending outside the circle may be read improperly

by the scanner. Be especially careful that your mark covers the center of its circle.

2. This Exam Booklet is Version A. Mark the A circle in the TEST FORM box near the

middle of your answer sheet. DO THIS NOW! WE WILL ASSESS A 1 POINT (RAW

SCORE) PENALTY FOR FAILURE TO DO THIS.

3. Print YOUR LAST NAME in the designated spaces at the left side of the answer sheet, and

then mark the corresponding circle below each letter. Do the same for your FIRST NAME

INITIAL.

4. Print your NETWORK ID in the designated spaces at the right side of the answer sheet,

starting in the left-most column, and then mark the corresponding circle below each

character. If there is a letter "o" in your NetID, be sure to mark the "o" circle, and not the

circle for the digit zero. If and only if there is a hyphen "-" in your NetID, mark the hyphen

circle at the bottom of the column. When you have finished marking the circles

corresponding to your NetID, check particularly that you have not marked two circles in any

one of the columns.

5. Do not write in or mark the circles in any of the other boxes (STUDENT NUMBER, DATE,

SECTION, SCORES, SPECIAL CODE).

6. Mark only one answer per question.

7. When told to do so: Check to make sure that the test booklet is complete. There are 11

numbered pages, including this cover sheet.

8. If you understand the statement below, please sign ( DO NOT PRINT ) your name in the

space provided. If you do not understand, please ask the professor for clarification.

Academic Integrity— Giving assistance to or receiving assistance from another student or using unauthorized materials during a University Examination can be grounds for disciplinary action, up to and including dismissal from the University

Page 1 of 8 pages

Suppose you are standing on a bathroom scale when you are flying in a jet airplane. For a moment the scale reads less than your actual weight. During that moment, it's exerting an upward force on you that is A) greater than your weight. B) equal to zero. C) equal to your weight. D) less than your weight.

2). Your class is delighted with your instructor, and as a reward, you all pitch in to fund a sabbatical for him to go to the Moon. Your dedicated instructor decides to continue the course the next semester, telecasting from the Moon. He begins talking about mass, weight and related things and correctly makes which following statement: A) his mass is still essentially unchanged but his weight is less than on earth. B) his weight is still essentially unchanged but his mass is less than on earth. C) neither his weight nor his mass have changed much. D) his weight and mass have both changed significantly.

You are extremely bored during the long summer months when school is out of session, so you decide to attach a graphing calculator to a rubber band and repeatedly bounce it up and down vertically. When the rubber band is at its maximum stretch away from your hand A) the calculator’s velocity is downward but its acceleration is upward. B) the calculator’s velocity is zero but its acceleration is upward. C) the calculator’s velocity is upward but its acceleration is downward. D) the calculator’s velocity is zero but its acceleration is downward.
Which system is in a state of stable equilibrium? A) A marble in the bottom of a spherical bowl. B) A marble on top of a spherical bowl. C) A marble on a flat, level surface. D) A marble rolling down an inclined surface.
You have watched one too many old cartoons and decide to drive around town with a giant spring that is 4 m long and attached to the front of your car. You decide to help a semi truck that is stuck and try to push them with your car. You take a running start, and when you contact the truck the spring in your car compresses 3 m. During which portion of the compression did you do the least work on the spring? A) During the second meter. B) During the third meter. C) During the first meter. D) The work done is equal for all segments of the trip.
Why do elastic balls bounce so well? A) They store energy through compression, like a spring. B) They permanently deform, storing energy. C) They are all filled with a special energy-absorbent liquid. D) They are always thrown well.
Cars are designed so that their bodies buckle (permanently deform) when they are in an accident. How does the buckling make the car safer by not allowing it to recoil (bounce) so much? A) The buckling stores energy. B) The buckling dissipates the energy of the crash. C) The buckling provides energy to the crashing objects. D) The buckling gives the car a high coefficient of restitution.

Page 2 of 8 pages

A) helps the bicycle accelerate inward to complete each turn without skidding. B) it does work on the bicycle during each turn and thus increases the bicycle's energy. C) balances the outward centrifugal force that the bicycle experiences as it completes each turn, so that the bicycle experiences zero net force. D) it does negative work on the bicycle during each turn and thus decreases the bicycle's energy.

You are flying on an airplane and you notice that a ball of aluminum foil from lunch starts to roll to the left. From the motion of the foil ball you can conclude that the plane is A) moving at constant velocity toward the right. B) turning toward the left. C) moving at constant velocity toward the left. D) turning toward the right.
When moving, a bicycle is in a state of dynamic equilibrium due to A) gyroscopic effects. B) air resistance. C) the shape of the fork. D) (A) and (C).
A three-wheeled vehicle is A) statically stable and dynamically unstable B) statically unstable and dynamically stable C) both statically and dynamically unstable D) both statically and dynamically stable
In studying many martial arts, it is necessary to practice efficient and safe postures. One important concept related to how one should stand is that the feet should be reasonably far apart, because A) the base of support is wider, thus stabilizing the person. B) the weight on each foot will be less than when standing normally. C) the weight on each foot will be more than when standing normally. D) the friction force increases, giving the person more traction.
It is important for cyclists to lean their bicycles while negotiating sharp turns because A) the torque created by their leaning balances out the frictional torque from the road which would tend to flip them. B) the torque created by their leaning balances out their weight and holds them up. C) their tires flatten out, thus getting better traction on the road. D) they increase their static stability
You are riding a multi-speed bicycle up a steep hill that's 100 m high and want to do as little work as possible on your way up the hill. A) You should choose the largest crank sprocket (attached to the pedals) and the smallest freewheel sprocket (attached to the rear wheel). B) You should choose the smallest crank sprocket (attached to the pedals) and the largest freewheel sprocket (attached to the rear wheel). C) You should choose the largest crank sprocket (attached to the pedals) and the largest freewheel sprocket (attached to the rear wheel). D) Your choice of gears doesn't matter because you'll do the same amount of work climbing the hill no matter which gear you choose.
Why does an ice cube feel cold?

Page 4 of 8 pages

A) Heat from your hand enters the cube by convection. B) Cold from the cube enters your hand by convection. C) Heat from your hand enters the cube by conduction. D) Cold from the cube enters your hand by conduction.

A pedestrian bridge crosses a street. This bridge is entirely supported by columns from below. A gap at each end of the bridge separates the bridge’s surface from the sidewalks leading to the bridge. The width of each gap changes with time. This width is smallest A) on hot days. B) at noon. C) at midnight. D) on cold day.
People fighting forest fires carry emergency tents that have shiny aluminum outer surfaces. If there is trouble, a fire fighter can lie under the tent to block the heat from burning trees overhead. The tent helps because A) conduction carries heat downward toward the fire fighter and the aluminum tent conducts that heat harmlessly into the ground. B) radiation carries heat downward toward the fire fighter and the aluminum tent reflects most of that radiation. C) convection carries heat downward toward the fire fighter and the aluminum tent blocks most of the heat carried by convection. D) both conduction and radiation carry heat downward toward the fire fighter and the aluminum tent blocks most of that heat.
Suppose you are teaching a science course and have prepared a demonstration to teach how a thermometer works. When you plunge the thermometer into hot water, one of your students points out that the mercury in the thermometer actually went down a little bit before it shot up. It behaved in such a way because A) The water pressure squeezed in on the mercury. B) The mercury contracted at first because of the temperature shock. C) The glass expanded before the mercury had a chance to, creating space. D) The thermometer lost heat to the surrounding water.
Soil heats up much faster than water when the two are exposed to sunlight. Use that fact and your understanding of heat transfer to predict which way the wind will blow near the surface of the earth as the sun rises near the seashore. A) The surface wind will blow from the land toward the water. B) The surface wind will blow alternately back and forth along the shore, parallel to the boundary between land and water. It will reverse directions every few minutes. C) The surface wind will blow steadily in one direction along the shore, parallel to the boundary between land and water. D) The surface wind will blow from the water toward the land.
Which temperature scale has 100 degrees as the boiling point of water? A) Fahrenheit B) Celsius C) Centigrade D) Kelvin E) Both B) and C)

Page 5 of 8 pages

An ordinary incandescent light bulb contains some inert gas inside its glass enclosure because the gas increases A) the filament’s life while causing a small decrease in the bulb’s energy efficiency. B) the bulb’s energy efficiency while causing a small decrease in the filament’s life. C) the filament’s temperature by providing it with extra chemical potential energy. D) both the filament’s life and the bulb’s energy efficiency.
Why is it possible for a red star to be brighter than a blue star at the same distance from us? A) The red star is reflecting more light. B) The red star is hotter tan the blue star. C) The red star could have less surface area, making its energy more compact. D) The red star could have more surface area.
What does a heat pump not do? A) Increase entropy B) Move heat from a low temperature region to a high temperature region C) Perform work on its surroundings D) Conserve energy
You open the refrigerator in your room and put in a case of room-temperature root beer. After an hour, the root beer is ice cold. If your room air did not exchange any heat with the outdoor air during that time, the room air will be A) colder because the refrigerator reverses natural heating, so that things get colder rather than hotter. B) colder because as the refrigerator struggles to cool the root beer, some of the cold it produces inevitably leaks out into the room as the result of imperfect insulation. C) warmer because the refrigerator will have pumped heat out of the root beer and into the room air. D) warmer because some of the heat from the root beer inevitably leaks out into the room as the result of imperfect insulation.
A thermoelectric cooler is a type of heat pump that uses electric power to move heat against its natural direction of flow. In other words, it takes energy from a system and transfers it to another system which is at a higher temperature. In such a heat pump A) the entropy of the system must be conserved. B) Newton's laws of motion prevent heat from moving from a cool region to a warm region. C) the cooler requires power input because the flow of heat from a cool region to a warm region alone would decrease the entropy (disorder) of the system. D) the cooler requires power input the flow of heat from a cool region to a warm region alone would violate the conservation of energy.
“The entropy of an isolated system never decreases.” Which Law of Thermodynamics is this? A) Zeroth B) First C) Second D Third
Which of the following quantities has no conservation law? A) Energy B) Angular momentum C) Entropy D) Momentum

Page 7 of 8 pages

In a car engine, the compression stroke involves the piston compressing the air/gas mixture so rapidly that virtually no heat loss can occur. In the compression stroke, the air/gas mixture A) heats because of friction between the gas and the cylinder. B) cools because the gas is radiating its energy away. C) heats because work is being done on the air/gas mixture. D) cools because the air/gas mixture is doing work on the piston.
The “strokes”, or “cycles” in a four – stroke engine are A) induction, compression, power, exhaust B) ignition, compression, power, exhaust C) ignition, induction, power, exhaust D) vacuum, compression, ignition, exhaust
To make it less likely that a car engine will “knock” (have its fuel/air mixture ignite too early), the engine is designed so that A) the fuel/air mixture is not compressed too tightly. B) the fuel/air mixture is compressed as tightly as possible. C) the fuel/air mixture remains cold until the sparkplug fires. D) the fuel/air mixture stays at atmospheric pressure until the sparkplug fires.
Moments before it is ignited by the spark plug, the mixture of fuel and air inside an automobile cylinder is compressed to very high density. During the compression process, the mixture’s A) temperature stays the same but its pressure rises. B) temperature rises dramatically and so does its pressure. C) temperature drops dramatically but its pressure rises. D) temperature rises dramatically but its pressure drops.
An old friend sells you his old Jaguar, which is a very high-power racing car. To maintain this car for a long time, you know you must only use A) low-octane fuel because the compression ration is so low. B) low-octane fuel because the compression ration is so high. C) high-octane fuel because the compression ratio is so low. D) high-octane fuel because the compression ratio is so high.

Hour Exam 2 | How Things Work - Fall 2006 | PHYS 140, Exams of Classical Physics

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Partial preview of the text

Download Hour Exam 2 | How Things Work - Fall 2006 | PHYS 140 and more Exams Classical Physics in PDF only on Docsity!

FRIDAY, MARCH 17, 2006: PLEASE NOTE CREDIT IS BEING GIVEN FOR

* Problem 15 (Version A) answers B OR D

* Problem 26 (Version A) answers B, C, OR E

THIS WILL BE REFLECTED IN YOUR GRADE, NOT YOUR ON-LINE EXAM

QUESTIONS

Please do not open this exam book until you are told to do so.

You will need

1. A #2 pencil

2. One scantron answer sheet

3. One exam question booklet

On the scantron answer sheet:

1. Use a #2 pencil. Do not use a mechanical pencil or pen. Darken each circle completely, but

stay within the boundary. If you decide to change an answer, erase vigorously: The scanner

sometimes registers incompletely erased marks as intended answers, and this can adversely

affect your grade. Light marks or marks extending outside the circle may be read improperly

by the scanner. Be especially careful that your mark covers the center of its circle.

2. This Exam Booklet is Version A. Mark the A circle in the TEST FORM box near the

middle of your answer sheet. DO THIS NOW! WE WILL ASSESS A 1 POINT (RAW

SCORE) PENALTY FOR FAILURE TO DO THIS.

3. Print YOUR LAST NAME in the designated spaces at the left side of the answer sheet, and

then mark the corresponding circle below each letter. Do the same for your FIRST NAME

INITIAL.

4. Print your NETWORK ID in the designated spaces at the right side of the answer sheet,

starting in the left-most column, and then mark the corresponding circle below each

character. If there is a letter "o" in your NetID, be sure to mark the "o" circle, and not the

circle for the digit zero. If and only if there is a hyphen "-" in your NetID, mark the hyphen

circle at the bottom of the column. When you have finished marking the circles

corresponding to your NetID, check particularly that you have not marked two circles in any

one of the columns.

5. Do not write in or mark the circles in any of the other boxes (STUDENT NUMBER, DATE,

SECTION, SCORES, SPECIAL CODE).

6. Mark only one answer per question.

7. When told to do so: Check to make sure that the test booklet is complete. There are 11

numbered pages, including this cover sheet.

8. If you understand the statement below, please sign ( DO NOT PRINT ) your name in the

space provided. If you do not understand, please ask the professor for clarification.

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