Name:

Exam 01: Chapters 01 – 03InstructionsPut your name on this test paper. When you complete the exam, the test paper must be submitted. This exam paper will be returned to you when it is graded.You may use your calculator and the formula sheet provided. You may not use your phone or any additional reference materials.Respond to each question using your clicker. Remember, only SUBMIT your answers after you have double-checked, and are satisfied with your responses. Clicking SUBMIT is the same as handing in your test paper, and you may not alter your responses after you submit them.Make sure that your phone is switched off. It should be put away, and nowhere visible on your desk. If your phone rings during the exam, you will be required to turn in your exam and leave the room. You will not be allowed to return and complete any unfinished portions of the exam. You may not use any type of mobile device as a calculator.

๏ Mark your answers on the test paper as well as clicking. Exams will not be scored by hand, but you definitely want a record of your responses in case some catastrophe strikes and data is lost.

๏ There is exactly one correct answer for each question.๏ Each question is worth 2 points.๏ There is no partial credit.

Formulas and ConstantsPythagorean Theorem:

Volume of a Cube:

Density:

Average velocity:

Acceleration:

Acceleration due to Earth’s gravity:

Newton #2:

Weight:

Impulse:

Linear Momentum:

Impulse-Momentum:

Conservation of Momentum:

Σp = m1v1 + m2v2 + ⋯ + mnvn

Law of Gravity:

€

F =G m1m2

r2

Work:

€

W = F ⋅ d

Power:

€

P =Wt

ScoringEach question is worth 2 points. Points: /100

P H Y S 1 4 0 0 : P H Y S I C A L S C I E N C E F O R G E N E R A L E D U C AT I O N S P R I N G 2 0 1 8

1. What is science?A) A rigid set of unchanging rules.B) A static collection of unchanging facts.C) A search for order and explanation of our physical

surroundings.D) A method for gathering, categorizing, analyzing, and

using information to explain the physical universe.E) Both A and B, but not C and D.F) Both C and D, but not A and B.

2. Ben-Hur, Titanic, and LOTR: Return of the King are the three movies which have earned the most Academy Awards (11 Oscars each). Why were we even discussing this in a physical science class?A) This is an example of a measurement which does not

objectively quantify a property.B) These are three movies that happen to show the laws of

physics incredibly accurately; there is no “cartoon” or fake physics in these particular films.

C) The number of Oscars earned by a movie is an objective measurement of the quality of the film. It’s a scientific fact that these three movies are the best movies in the history of cinema.

3. If I say (as I did in class), “Titanic is 195!”, how do you respond? (Choose the response consistent with the context of our in-class discussion!)A) “Yes! 195 is the best possible number, and Titanic is

the best possible movie, so I agree completely!”B) “Yes! 195 is divisible by 7, and Titanic has 7 letters. It

can’t possibly be a coincidence!”C) “No! A number is not a movie, and even if it was, it

couldn’t possibly be a ship as well. You’re insane.”D) “Maybe...it depends on what you mean by ‘195.’

Without units, I don’t understand your statement!”

4. In the English (or Imperial) system of units, length can be measured in yards. What is the referent for this measurement?A) A yard is the approximate average length of a human

stride.B) A yard is literally derived from the average length of a

human foot.C) The average length from the street to the back fence of a

typical suburban house lot is a yard.D) Half the length of the typical lanyard cord (like the kind

for ID badges) is a demi-yard, or just a yard for short.

5. Who uses the metric system (or Système Internationale)?A) Everyone; this is the agreed-upon standard system for

all of the countries in the world. Well, except for the US, Liberia, and Myanmar.

B) Hardly anyone; only the Unites States, Liberia, and Myanmar still use this system of measurement.

C) No one; this system of units fell out of favor in the late 1700s, and has not been used since.

6. True or false: The kilogram (unit of mass) is a derived unit.

7. Which of the following is a fundamental unit?A) length D) momentumB) velocity E) These are all examples ofC) acceleration fundamental units!

8. How long is one metric second?A) A metric second is approximately 1/10 of an English (or

Imperial) second.B) A metric second is approximately 1.1 times longer than

an English (or Imperial) second.C) A metric second cannot be measured, so it cannot be

compared to an English (or Imperial) second.D) Trick question! A second is a second. There is no

difference between a “metric” or an “English” second!

9. If you are measuring the time for google to complete a search, what units would be the most appropriate?A) nanometers = 10–9m D) kilograms = 103gB) milliseconds = 10–3s E) megayears = 106yearsC) centimeters = 10–2m F) terabytes = 1012bytes

10. When you calculate a ratio, what are you actually doing?A) Comparing. A ratio, or fraction, just compares two

quantities.B) Graphing. Calculating a ratio is the same thing as

constructing a pie chart.C) Judging. By constructing a ratio, you are judging which

of the quantities is actually better.D) Math. The calculation of anything is just math, and does

not have any relationship to the actual physical world.

Trial diameter d(cm)

circumference c (cm)

ratio c/d(unitless)

1 10 31.5 3.15

2 30 93.9 3.13

3 50 157 3.14

4 70 220 3.14

11. Complete the Trial 3 row of the table above by calculating the ratio of circumference to diameter, c/d. Answer numerically, with two decimal places (and no units).

12. What method would you use to predict the circumference of the 70cm diameter circle?A) Guess. The best you can do is pick a random number.B) Add the previous two circumference measurements

together to get the next measurement.C) Subtract the previous two circumferences. The

difference will be the circumference of the next object.D) Multiply the diameter by the average c/d ratio

calculated for the previous measurements.E) Divide the diameter by the average c/d ratio calculated

for the previous measurements.

13. Using the above table as a reference, predict the circumference of a circle with diameter d = 70 cm. Answer numerically, rounding your answer to the nearest integer (no decimal places or units).

14. A cube of iron has sides with length l = 2 cm. When measured on a balance, its mass is m = 62.9 g. Calculate the density ρ of this cube.

A) ρ = 2.89 g/cm3 D) ρ = 15.7 g/cm3

B) ρ = 7.86 g/cm3 E) ρ = 31.4 g/cm3

C) ρ = 11.2 g/cm3 F) ρ = 126 g/cm3

E X A M 0 1 : C H A P T E R S 0 1 – 0 3 S P R I N G 2 0 1 8

PAGE 02/05

15. The force of gravity follows an inverse-square law. Let’s say you decrease the distance between two masses, from r1 = 2m to r2 = 1m. What happens to the gravitational force between the masses as a result?A) Half the distance, ½ the force: F2 = ½F1.B) Half the distance, ¼ the force F2 = ¼F1.C) Half the distance, 2× the force F2 = 2F1.D) Half the distance, 4× the force F2 = 4F1.E) Half the distance, no change in the force F2 = F1.

16. The steps of the scientific methodA) are linear. Each step in the process must be followed in

order, or you cannot expect to achieve reproducible results.

B) are exhausting. There are so many steps involved that no one actually understands them or follows them.

C) are random. Scientific progress almost always occurs randomly, when a scientist makes a discovery by accident while looking for something else.

D) are iterative. When science gets done in the real world, the process of inquiry, experimentation, and revision may repeat itself many times.

E) are imaginary. Scientists don’t actually have a process they follow. Like artists, they create scientific theories with their imagination. The results are typically untested, because they are usually untestable!

17. How does an hypothesis differ from a scientific theory?A) An hypothesis is a wild, crazy guess. A theory is an

informed, or educated, guess. Neither has been proven.B) An hypothesis is an educated guess that has been

tested. A theory is a random idea that can't be proved.C) An hypothesis is an educated guess. It can become a

theory after is has been well–tested and is not shown to be false.

D) There is no difference; the words mean exactly the same thing, but tend to be used differently. People typically say "hypothesis" when they mean a respected idea, but call something they think is crazy a "theory."

18. When presented with experimental evidence which contradicts or disproves his hypothesis, a scientist mustA) always throw away the entire hypothesis and start over

from scratch.B) continue to support his hypothesis without modifying it.

Experiments are meaningless.C) resign from his research group. Scientists who can’t

prove their hypotheses are no scientists at all.D) examine both the evidence and the hypothesis. The

experiment may need to be redesigned, or the hypothesis may need to be revised–or maybe both.

19. Gravity is an example ofA) a scientific hypothesis. The idea of gravity can be

tested, but it never has been.B) a scientific theory. It has been tested repeatedly, over

literally centuries. Gravity works the same way every-where in the universe that humans have observed it.

C) a non-scientific opinion. No one really understands how “gravity” works, and no one has ever been able to devise a scientific test for it.

D) a crazy, pseudo-scientific belief system. Most people understand that “gravity” is not a scientific idea at all, just a term used to dismiss observations that cannot be explained using the easily proven Flat Earth Theory.

20. Which of the following is not an indicator of pseudoscience?A) Using words that sound professional or scientific in a

misleading or incorrect way.B) Substantial reliance on anecdotal evidence.C) Claims which cannot be proven false.D) Absence of adequate peer review.E) These are all hallmarks of pseudoscience!

4ft 3ftc

A B

C

The keys shown above are initially at rest on the table at point A. You slide them from A to B to C, and leave them again at rest at point C.21. True or false: The displacement of the keys is greater than

the distance traveled.22. True or false: The displacement of the keys is 7ft.23. True or false: It is possible for an object to travel some non-

zero distance, but have a zero displacement.24. Velocity is an example of a vector. What exactly is a vector?

A) Vector is a unit, like meters or seconds. Vector just happens to be the name of the metric unit of force.

B) Vector is another way of saying very, very large. A vector quantity must be written in scientific notation.

C) A vector is a physical quantity for which both a size (or magnitude) and a direction are meaningful and relevant.

D) A vector is a physical constant. A random number (like 5) is not a vector, but pi (3.14) is a vector because it has meaning.

25. Which of the following is not a vector quantity?A) Time D) AccelerationB) Displacement E) ForceC) Velocity F) Momentum

26. Car A drives east on College Avenue at 30 mph. Car B drives west on Prince Street, also at 30 mph. The cars haveA) the same speed, same velocity.B) the same speed, but different velocities.C) the same direction, same velocity.D) the same direction, but different velocities.E) neither the same speed nor the same direction!

27. You sit in your favorite chair and lace up your running shoes. You leave the house, run three miles, and return to your favorite chair to remove your shoes. The whole thing took you thirty minutes (0.5 hour).A) Both your average speed and your average velocity are

exactly zero.B) Your average velocity was (3miles/0.5hr) = 6mph, but

your average speed was zero.C) Backwards! Your average speed was 6 mph, but your

average velocity was zero.D) The average speed is exactly the same as average

velocity, and both are 6 mph.

E X A M 0 1 : C H A P T E R S 0 1 – 0 3 S P R I N G 2 0 1 8

PAGE 03/05

2 4 6 8 10

4

8

12

The graph above shows the velocity of a car as function of time. Use this graph to answer Questions 28 and 29.28. What is happening to the car during Interval B?

A) Nothing. The vehicle is at rest, with no motion at all.B) The car has changed direction. For example, if it was

headed north during Interval A, it’s heading south during Interval B, at the same speed.

C) The car has not changed direction, but its speed is not increasing anymore. The speed stays constant (8m/s) over the entire interval (from 2 seconds to 6 seconds).

29. What’s the acceleration during Interval C? Answer numerically, with no decimal places. Include the sign if necessary, but no units.

30. A car navigates a curved freeway offramp with a constant speed of 35 mph.A) Because the car maintains a constant speed, it is not

accelerating.B) Not possible, because there is no way any vehicle can

navigate any curve without speeding up.C) Even if the speed remains constant, the changing

direction of the vehicle means it has an acceleration.

31. What does an object’s inertia (measured by mass) tell you?A) The size of the object. The larger the volume of the

object, the greater its inertia.B) The weight of the object. The greater the weight the

object has, the less inertia is has.C) The density of the object. The greater the density of the

object, regardless of its mass or size, the greater its inertia.

D) The resistance to electricity. The greater the inertia, the more the object resists electrical current.

E) The resistance to change. The greater the inertia, the more an object resists a change in its motion.

32. According to Newton’s First Law of Motion, objects at restA) are not really at rest; every object is, in fact, in motion.B) will remain at rest, unless acted upon by an

unbalanced force.C) will begin to move spontaneously, as motion is the

natural state for all mass.D) cannot experience forces. That’s why they are at rest,

because it is not possible to exert any force upon them.E) cannot be made to move; there are no circumstances

under which stationary objects can change their state of motion.

33. You watch as a hockey puck slides across the ice, traveling several meters before coming to rest. According to Newton’s First Law,A) objects without mass cannot move, so the puck must

have zero mass.B) objects in motion want to be at rest, so the puck

naturally stops moving.C) objects in motion want to remain in motion, so some

force must have acted upon the puck to stop it moving.

34. You notice that when you apply a horizontal force to a an object with mass m1 = 4kg, its acceleration is a1 = 1m/s2. According to Newton’s Second Law of Motion, if you apply the exact same horizontal force to a second object with m2 = 8kg, how much will it accelerate?A) If the forces are the same, the acceleration of each

object must also be exactly the same, regardless of their different masses: a2 = a1 = 1m/s2.

B) If Object 2 has twice the mass, the same force will provide twice the acceleration: a2 = 2a1 = 2m/s2.

C) If Object 2 has twice the mass, applying the same force will only give half the acceleration: a2 = ½a1 = 0.5m/s2.

D) There is no relationship between the forces and the accelerations, so there is no way to predict what will happen.

35. Calculate the acceleration of the lawnmower if your friend pushes it with a horizontal force F = 65N. The mass of the mower is m = 25kg. Answer numerically with one decimal place.

36. The Earth has an acceleration due to gravity g = 9.8 m/s2. However, on Mars the value for g = 3.71 m/s2. On Earth, a 100kg mass weighs w= mg =(100kg)(9.8m/s2)=980NHow much does a 100kg mass weigh on Mars? Answer numerically, rounding to the nearest integer (no units, no decimal places.)

37. Two separate forces are acting on the same object. The force of gravity pulls a sheet of paper downward, but air resistance exerts a force upwards on the sheet.A) This might be an example of Newton #3, but only if the

forces act in the same direction.B) This might be an example of Newton #3, but only if the

two forces act in opposite directions.C) This is always an example of Newton #3. Any two forces

acting on the same object form an action-reaction pair.D) This is never an example of Newton #3; an action-

reaction force pair always acts on two different objects.

E X A M 0 1 : C H A P T E R S 0 1 – 0 3 S P R I N G 2 0 1 8

PAGE 04/05

38. Tiny (the elephant) applies 150N of force to Ike (the dude in the wig). How much force does Ike apply to Tiny?A) Exactly 0N. D) Exactly 100N.B) Maybe 50N. E) Exactly 150N.C) About 75N. F) No way to tell!

39. If Ike has a mass of 60kg, then that 150N push gives him an acceleration aI = 2.50m/s2. Tiny, though, has a whopping mass mT = 1000kg! What is the magnitude aT of Tiny’s acceleration?A) Zero: aT = 0.B) Less than Ike’s acceleration: aT < aI.C) Equal to t Ike’s acceleration: aT = aI.D) Greater than Ike’s acceleration: aT > aI.

D

E

AB

C

Billiard balls having identical mass are shown above in a long-exposure photograph. Use the photo to respond to Questions 40 and 41.

40. Of the balls labeled A through E, which has the smallest momentum? Ball C

41. Compare the momentum vectors for Ball A and Ball E.A) Both vectors have the same magnitude and direction.B) The magnitudes of both are almost identical, but the

vector directions are different.C) The magnitudes of the vectors are very different, but the

directions are identical.D) The magnitudes of the vectors are very different, and

their directions are different as well.E) There cannot be a comparison, because Ball A has

momentum, but Ball E does not.

42. Object A has momentum pA = +50kg·m/s, while Object B has momentum pB = –50kg·m/s. From this information, you know that bothA) are both at rest.B) have the same mass.C) have the same speed.D) are traveling in the same direction.E) are traveling in opposite directions.

A car with mass mA = 3000 kg is traveling east with a speed vA = +5 m/s. A second car (mB = 2000 kg) also travels east, but with a speed vB = +9 m/s. Unfortunately, car B runs right into the back of car A.43. What is the total system momentum (pi = carA + carB) at

the instant just before the collision?A) pi = 0 kg·m/s. D) pi = 18,000 kg·m/s.B) pi = 14 kg·m/s. E) pi = 33,000 kg·m/s.C) pi = 15,000 kg·m/s. F) pi = 70,000 kg·m/s.

44. What is the total system momentum (pf = carA + carB) at the instant just after the collision?A) Zero: pf = 0.B) Less than the initial momentum: pf < pi.C) Equal to the initial momentum: pf = pi.D) Greater than the initial momentum: pf > pi.

45. True or false: After the collision, the momentum of car A (by itself) will be unchanged. However much momentum it had prior to the collision, it will have exactly the same amount afterwards.

46. In the context of physics, work isA) a vector quantity representing an object’s state of

motion.B) a scalar quantity representing the process by which an

object’s state of motion can be changed.C) a constant quantity representing the mass of an object.D) that thing you do every day to earn a paycheck.

47. Surprise! The cat is knocking things off the table again. He applies a horizontal force F = 0.5N to an eyeglass case with a mass of 120g (m = 0.120kg). How much work did the cat do to move the case 15cm (d = 0.15m) across the table?A) W = 0.018J C) W = 0.075J E) W = 0.300JB) W = 0.060J D) W = 0.240J F) W = 0.800J

48. How much work does the force of gravity do on the case as it moves across the table?A) W = [(0.120kg)(9.8m/s2)]×(0.15m) = 0.176JB) W = (0.120N)×(0.15 m) = 0.018JC) W = (0.5N)×(0.15m) = 0.075JD) W = 0. Gravity is perpendicular to the motion!

49. An object is in motion when a force is applied to it. The force does negative work on the object. What does this mean? Doing negative work on an objectA) will slow it down.B) will speed it up.C) will cause no change to its motion.D) will change its direction of motion (i.e., from +x to –y).

50. How much power is developed when a 500kg elevator rises through 10 stories (30m) in a time of 60 seconds?A) P = 0W C) P = 250W E) P = 1000WB) P = 83.3W D) P = 600W F) P = 2450W

E X A M 0 1 : C H A P T E R S 0 1 – 0 3 S P R I N G 2 0 1 8

PAGE 05/05