Multiple Choice Identify the choice that best completes the statement or answers the question.

Transcription

1 Physics Fall 2014 Review Multiple Choice Identify the choice that best completes the statement or answers the question. Choose the best answer from the options that follow each question. 1. Physics is concerned with which of the following matters? a. applying physics principles b. describing the physical world c. making predictions about a broad range of phenomena d. all of the above 2. Measuring temperature would most likely involve which major area in physics? a. optics b. thermodynamics c. relativity d. vibrations and wave phenomena 3. A physicist who studies the behavior of submicroscopic particles is working in which area within physics? a. mechanics b. electromagnetism c. relativity d. quantum mechanics 4. After making observations and collecting data that leads to a question, a physicist will then a. formulate and test hypotheses by experimentation. b. state conclusions. c. interpret the results. d. revise the initial hypotheses. 5. How many variables may be tested legitimately in any one experiment? a. as many as a physicist can handle b. three c. one d. five 6. Why do physicists use models? a. They are usually easy to build. b. They are helpful when explaining fundamental features. c. They are usually inexpensive. d. none of the above 7. Which of the following represents a system? a. flag blowing in the wind b. ball rolling on the ground c. picture hanging on the wall d. all of the above 8. Models can do all of the following except a. explain every aspect of natural phenomena. b. help build hypotheses. c. guide experimental design. d. make predictions in new situations.

2 Choose the best answer from the options that follow each question Based on the data from Table 1, which of the following statements is correct? a. The temperature increased equally during each time period for both substances. b. There is no relationship between heating time and temperature for either substance. c. As time increased, the temperature increased for both substances. d. none of the above What does Graph 1 show about the heating rate of substance A versus substance B? a. Compared to substance B, substance A has a faster heating rate. b. Compared to substance A, substance B has a slower heating rate. c. Substance A and B heat at different rates. d. all of the above 11. Which of the following equations best shows the average relationship between temperature and time for substance B as given in Table 1 and Graph 1 above? a. T = 0.07( t) b. T = 0.07( t) 2 c. ( T) 2 = 0.7( t) d. T = 7.4( t)

3 12.What does the symbol m represent? a. change in mass b. change in meters c. difference in motion d. distance in meters 13. What is the standard abbreviation for seconds? a. sec b. s c. sds d. t 14. All of the following are unit abbreviations except which one? a. m b. kg c. y d. s 15. If the final answer s dimension is to be in length, which of the following operations is correct? a. (time/length) time b. time (length/time) c. (time length) - length d. length (length/time) 16. Using the order-of-magnitude method of calculation, estimate how long it would take a car moving at 109 km/h to travel km. a h b h c h d. 100 h Choose the best answer from the options that follow each question. 17. Which of the following is an area of physics that studies motion and its causes? a. thermodynamics b. mechanics c. quantum mechanics d. optics 18. Listening to your favorite radio station involves which area of physics? a. optics b. thermodynamics c. vibrations and wave phenomena d. relativity 19. A baker makes a loaf of bread. Identify the area of physics that this involves. a. optics b. thermodynamics c. mechanics d. relativity 20. According to the scientific method, why does a physicist make observations and collect data? a. to decide which parts of a problem are important b. to ask a question c. to make an interpretation d. to solve all problems

4 21. In the steps of the scientific method, what is the next step after formulating and objectively testing hypotheses? a. interpreting results b. stating conclusions c. conducting experiments d. making observations and collecting data 22. Why do physicists use models? a. to explain the complex features of simple phenomena b. to describe all aspects of a phenomenon c. to explain the basic features of complex phenomena d. to describe all of reality 23. Which statement about models is not correct? a. Models describe only part of reality. b. Models help build hypotheses. c. Models help guide experimental design. d. Models manipulate a single variable or factor in an experiment. 24. What two dimensions, in addition to mass, are commonly used by physicists to derive additional measurements? a. length and width b. area and mass c. length and time d. velocity and time 25. The symbol mm represents a a. micrometer. b. millimeter. c. megameter. d. manometer. 26. The SI base unit used to measure mass is the a. meter. b. second. c. kilogram. d. liter. 27. The SI base unit for time is a. 1 day. b. 1 hour. c. 1 minute. d. 1 second. 28. A lack of precision in scientific measurements typically arises from a. limitations of the measuring instrument. b. human error. c. lack of calibration. d. too many significant figures. 29. How does a scientist reduce the frequency of human error and minimize a lack of accuracy? a. Take repeated measurements. b. Use the same method of measurement. c. Maintain instruments in good working order. d. all of the above

5 30. Five darts strike near the center of a target. The dart thrower is a. accurate. b. precise. c. both accurate and precise. d. neither accurate nor precise. 31. Calculate the following, and express the answer in scientific notation with the correct number of significant figures: a b c d Hour Temperature ( C) 1: : : : : : A weather balloon records the temperature every hour. From the table above, the temperature a. increases. b. decreases. c. remains constant. d. decreases and then increases.

6 33. The time required to make a trip of km is measured at various speeds. From the graph above, what speed will allow the trip to be made in 2 hours? a km/h b km/h c km/h d km/h 34. The Greek letter indicates a(n) a. difference or change. b. sum or total. c. direct proportion. d. inverse proportion. 35. The most appropriate SI unit for measuring the length of an automobile is the a. micron. b. kilometer. c. meter. d. nanometer. 36. Estimate the order of magnitude of the length of a football field. a m b m c m d m 37. A hiker uses a compass to navigate through the woods. Identify the area of physics that this involves. a. thermodynamics b. relativity c. electromagnetism d. quantum mechanics

7 38. According to the scientific method, how does a physicist formulate and objectively test hypotheses? a. by defending an opinion b. by interpreting graphs c. by experiments d. by stating conclusions 39. Diagrams are not designed to a. show relationships between concepts. b. show setups of experiments. c. measure an event or a situation. d. label parts of a model. 40. The most appropriate SI unit for measuring the length of an automobile is the a. micron. b. kilometer. c. meter. d. nanometer. 41. The radius of Earth is m. Express this measurement in km in scientific notation with the correct number of significant digits. a km b km c km d km 42. Three values were obtained for the mass of a metal bar: 8.83 g; 8.84 g; 8.82 g. The known mass is g. The values are a. accurate. b. precise. c. both accurate and precise. d. neither accurate nor precise. 43. Calculate the following, and express the answer in scientific notation with the correct number of significant figures: a b c d Calculate the following, and express the answer in scientific notation with the correct number of significant figures: ( )( ) a b c d. 3784

8 45. Which of the following equations best describes the graph above? a. y = 2x b. y = x c. y = x 2 d. y = x 46. Which of the following equations best describes the graph above? a. y = x 2 1 b. y = x 2 1 c. y = x 2 1 d. y = x 2 1

9 47. Which expression has the same dimensions as an expression yielding a value for acceleration (m/s 2 )? ( v has units of m/s.) a. v/( t) 2 b. v/( x) 2 c. ( v) 2 / t d. ( v) 2 / x 48. If the change in position x is related to velocity v (with units of m/s) in the equation x = Av, the constant A has which dimension? a. m/s 2 b. m c. s d. m The sun is composed mostly of hydrogen. The mass of the sun is kg, and the mass of a hydrogen atom is kg. Estimate the number of atoms in the sun. a b c d What is the speed of an object at rest? a. 0.0 m/s b. 1.0 m/s c. 9.8 m/s d m/s 51. Which of the following situations represents a negative displacement? (Assume positive position is measured vertically upward along a y-axis.) a. A cat stands on a tree limb. b. A cat jumps from the ground onto a tree limb. c. A cat jumps from a lower tree limb to a higher one. d. A cat jumps from a tree limb to the ground. 52. Which of the following units is the SI unit of velocity? a. meter b. meter second c. meter per second d. second per meter 53. In the graph above, a toy car rolls from 13 m to 15 m. Which of the following statements is true? a. x f = +3 m b. x i = +3 m c. x = +3 m d. v avg = 3 m/s 54. The slope of a line drawn tangent to a point on the curve of a position versus time graph describes what concept? a. acceleration b. displacement c. instantaneous velocity d. position

10 55. Acceleration is defined as a. a rate of displacement. b. the rate of change of displacement. c. the change in velocity. d. the rate of change of velocity. 56. What is the SI unit of acceleration? a. m/s b. m 2 /s c. m/s 2 d. m s If you know a car s acceleration, the information you must have to determine if the car s velocity is increasing is the a. direction of the car s initial velocity. b. direction of the car s acceleration. c. initial speed of the car. d. final velocity of the car. 58. If you know the acceleration of a car and its initial velocity, you can predict which of the following? a. the direction of the car s final velocity b. the magnitude of the car s final velocity c. the displacement of the car d. all of the above 59. When a car s velocity is positive and its acceleration is negative, what is happening to the car s motion? a. The car slows down. b. The car speeds up. c. The car travels at constant speed. d. The car remains at rest. 60. The graph below describes the motion of a ball. At what point does the ball have an instantaneous velocity of zero? a. A b. B c. C d. D 61. The motion of a ball on an inclined plane is described by the equation x = 1/2a( t) 2. This statement implies which of the following quantities has a value of zero? a. x i b. x f c. v i d. t f

11 62. Acceleration due to gravity is also called a. negative velocity. b. displacement. c. free-fall acceleration. d. instantaneous velocity. 63. When there is no air resistance, objects of different masses dropped from rest a. fall with equal accelerations and with equal displacements. b. fall with different accelerations and with different displacements. c. fall with equal accelerations and with different displacements. d. fall with different accelerations and with equal displacements. 64. Objects that are falling toward Earth in free fall move a. faster and faster. b. slower and slower. c. at a constant velocity. d. slower then faster. 65. Which would hit the ground first if dropped from the same height in a vacuum a feather or a metal bolt? a. the feather b. the metal bolt c. They would hit the ground at the same time. d. They would be suspended in a vacuum. 66. Which of the following situations represents a positive displacement of a carton? Assume positive position is measured vertically upward along a y-axis. a. A delivery person waiting for an elevator lowers a carton onto a dolly. b. When the elevator doors open, the delivery person lifts the dolly over the threshold of the elevator. c. The delivery person pushes the dolly to the back of the elevator while pressing a floor button. d. The door closes and the elevator moves from the 10th to the 4th floors. Refer to the figure below to answer the following questions. 67. What is the correct description of any change of position farther to the right of zero? a. positive displacement b. positive distance c. positive position d. positive change of displacement 68. A dog walks from +4 m to +2 m. Which of the following statements is true about the dog s motion? a. x i = +2 m b. x f = +2 m c. x = +2 m d. v avg = 2 m/s 69. What is the maximum negative displacement a dog could have if it started its motion at +3 m? a. +7 m b. +3 m c. +3 m d. +7 m

12 70. Rank in decreasing order the displacements of objects having the following pairs of average velocity and time of motion. I. v avg = +2.0 m/s, t = 2.0 s II. v avg = +3.0 m/s, t = 2.0 s III. v avg = -3.0 m/s, t = 3.0 s a. I, II, III b. II, III, I c. II, I, III d. III, II, I 71. Rank in decreasing order the distances traveled by objects having the following pairs of average velocity and time of motion. I. v avg = +2.0 m/s, t = 2.0 s II. v avg = +3.0 m/s, t = 2.0 s III. v avg = -3.0 m/s, t = 3.0 s a. I, II, III b. II, III, I c. II, I, III d. III, II, I The graph below shows the motion of a dog pacing along a fence. Refer to the graph to answer the following questions. 72. For the five time intervals shown, during how many intervals does the dog have the same average velocity? a. 0 b. 1 c. 2 d For the five time intervals shown, during how many intervals does the dog pace at the same average speed? a. 0 b. 1 c. 2 d. 3

13 74. The average acceleration is the ratio of which of the following quantities? a. d: v b. d: t c. v: v d. v: t 75. The speed of a car will increase if the car s a. initial velocity is positive and its acceleration is zero. b. initial velocity is positive and its acceleration is positive. c. initial velocity is positive and its acceleration is negative. d. initial velocity is negative and its acceleration is positive. 76. For a scooter with a negative acceleration, which of the following statements is always true? a. The scooter is losing speed. b. The final velocity of the scooter will be negative. c. The initial velocity of the scooter will be greater than its final velocity. d. The scooter will have a negative displacement. The following questions refer to the following velocity-time graph of a jogger. The positive direction is away from the jogger s home. 77. The jogger is at rest during which interval? a. AB b. BC c. DE d. EF 78. During which of the following intervals does the jogger have a constant positive velocity? a. BC b. CD c. DE d. FG 79. During which interval is the magnitude of the jogger s acceleration the greatest? a. AB b. BC c. DE d. EF

14 80. During which of the following intervals is the speed of the jogger decreasing? a. AB only b. AB and CD c. AB, CD, and EF d. EF only 81. During which of the following intervals is the jogger s motion toward home? a. CD and EF b. DE only c. EF only d. EF and FG 82. What is the SI base unit for length? a. meter b. kilogram c. kilometer d. second 83. What quantity does the kilogram measure? a. time b. distance c. force d. mass 84. In scientific notation, mm equals a mm. b km. c mm. d m. 85. In scientific notation, µg equals a µg. b g. c mg. d. all of the above 86. The average mass of a proton is kg. What is this mass in grams? a g b g c g d g 87. The accepted value for free-fall acceleration is m/s 2. Which of the following measurements is the most accurate? a m/s 2 b m/s 2 c m/s 2 d m/s Precision describes a. human error. b. the relationship of a measurement to an accepted standard. c. the limitations of the measuring instrument. d. the lack of instrument calibration.

15 89. How many significant figures does have? a. five b. seven c. two d. three 90. An object in free fall a. experiences no air resistance. b. undergoes a downward acceleration. c. has an acceleration with a magnitude of 9.81 m/s 2 near Earth s surface. d. all of the above 91. An object in free fall a. experiences an increase in speed of 9.81 m/s during each second. b. moves only downward. c. undergoes a velocity decrease of 9.81 m/s during each second. d. all of the above 92. The displacement of an object undergoing free fall from rest is proportional to a. t. b. t. c. ( t) 2. d. (2t) The final velocity of an object undergoing free fall from rest is proportional to a. x. b. x. c.. d. ( x) The graph below shows the motion of four objects. Which of the following lines represent an object in free fall? Assume positive velocity is upward. a. I only b. II only c. I and III d. I and IV

16 A red ball is dropped from rest and undergoes free fall. One second later a blue ball is dropped from rest and undergoes free fall. 95. The red ball? s change of velocity during the third second of the demonstration is v 2 3.What is the change of velocity of the blue ball during this time interval? a. v 2 3 b. v 2 3 c. 2 v 2 3 d. 3 v The red ball? s velocity at the end of 3.0 seconds is v 3. What is the blue ball s velocity at this moment of the demonstration? a. v 3 b. c. d. v 3 v 3 v The displacement of the blue ball during the time interval s is equal to the displacement of the red ball in which of the following intervals of the demonstration? a s b s c s d s Choose the best answer from the options that follow each question. 98. Which of the following is the equation for average velocity? a. v avg = b. v avg = c. v avg = x t d. v avg =

17 Use the graph below to answer the following questions. 99. During which interval is the cat at rest? a s b s c s d s 100. The cat has the fastest speed during which interval? a s b s c s d s 101. During which interval does the cat have the greatest positive velocity? a s b s c s d s 102. Which of the following is the equation for acceleration? a. a = b. a = c. a = v t d. a = 103. When a car s velocity is negative and its acceleration is negative, what is happening to the car s motion? a. The car slows down. b. The car speeds up. c. The car travels at constant speed. d. The car remains at rest.

18 104. What does the graph below illustrate about acceleration? a. The acceleration varies. b. The acceleration is zero. c. The acceleration is constant. d. The acceleration increases then becomes constant In the graph below, how does the acceleration at A compare with the acceleration at B? a. The acceleration at A is positive and less than the acceleration at B. b. The acceleration at B is positive and less than the acceleration at A. c. The accelerations at A and B are each zero. d. The accelerations at A and B cannot be determined Which of the following line segments on a velocity versus time graph is physically impossible? a. horizontal line b. straight line with positive slope c. straight line with negative slope d. vertical line

19 107. In the graph below, at what point is the speed of the ball equal to its speed at B? a. A b. C c. D d. none of the above 108. A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball s path does it experience zero velocity and nonzero acceleration at the same time? a. midway on the way up b. at the top of its path c. the instant it leaves the catcher s hand d. the instant before it arrives in the catcher s mitt 109. In a diagram, the length of a vector arrow represents the a. type of vector. b. direction of the vector. c. magnitude of the vector. d. cause of the vector Which of the following quantities used to describe motion is an example of a vector quantity? a. distance b. speed c. time d. average velocity 111. A vector remains unchanged a. if it is moved in any direction. b. only if it is moved parallel to its original direction. c. only if it is rotated perpendicular to its original direction. d. only if it is not moved.

20 Refer to the figure below to answer the following questions Which of the displacements, when added in the order given, will yield a displacement equal to d 1 + d 2 + d 3? a. d 3 + d 4 + d 1 b. d 2 + d 1 + d 3 c. d 2 + d 4 + d 3 d. d 4 + d 3 + d Which of the following represents the vector resulting in the subtraction of the displacement vectors d 2 d 1 shown in the figure? a. b. c. d In the figure, a. d 1 = d 4. b. d 1 = 2d 4. c. d 2 = 22d 4. d. d 3 = d If vectors are moved according to the rules of the triangle method of vector addition, then the resultant vector is drawn a. from the tail of the first vector to the tail of the last vector. b. from the tail of the first vector to the tip of the last vector. c. from the tip of the first vector to the tail of the last vector. d. from the tip of the first vector to the tip of the last vector A skier slides onto a horizontal patch of slushy snow at velocity v skier, and slows to a constant speed without changing direction. Which of the following expressions could be the skier s resulting velocity? a. -3v skier b. + v skier c. - v skier d. all of the above

21 117.In a diagram, a student draws a vector representing the velocity of a plane traveling at 525 km/h 18.0 east of north as a vector lying along the +x-axis. To represent the velocity of another plane traveling at 478 km/h 75.0 east of north on the diagram, at what orientation with respect to the +x-axis should the student draw this vector? a clockwise from the +x-axis b clockwise from the +x-axis c clockwise from the +x-axis d counterclockwise from the +x-axis 118. In question 1, another student chose east as the direction of the +x-axis. At what orientation with respect to the +x-axis should this student draw the vector representing the velocity of the second plane? a. parallel to the +x-axis b clockwise from the +x-axis c clockwise from the +x-axis d counterclockwise from the +x-axis 119. In a school playground, a child runs 5 m in the x-direction and then 2.0 m in the -y-direction. Which of the following expressions represents the magnitude of the child s resultant displacement? a. (5 m) 1 (22 m) b. c. d In the triangle below, what does equal? a. b. c. d. tan -1 tan -1 tan -1 tan The projection of a vector along the axes of a coordinate system is called a. a component of the vector. b. a tangent of the vector. c. the resultant of the vector. d. the magnitude of the vector.

22 122. The components of a vector are a. each equal to half the magnitude of the vector. b. independent of the orientation of the vector. c. perpendicular. d. vector quantities A vector that has components that lie along the -x-axis and the +y-axis is oriented at angle A measured counterclockwise from the +x-axis. Which of the following ranges give the values of angle A? a. 0 < A < 90 b. 90 < A < 180 c. 180 < A < 270 d. 270 < A < If the x-component of B equals the magnitude of B, then a. both components are equal. b. B y equals c. B y equals zero. d. B y lies along the -y-axis Which of the following may be classified as projectile motion? a. a punted football b. a thrown baseball c. a water droplet cascading down a waterfall d. all of the above 126. In the absence of air resistance, the path of a projectile is a(n) a. parabola. b. arc. c. polygon. d. semicircle The motion of a projectile in free fall is characterized by a. a x = a y = -g. b. a x = constant and v y = constant. c. v x = constant and a y = -g. d. v x = constant and v y = constant For an object to be a projectile, it must be in free fall and its initial velocity must a. have a horizontal component. b. have both a vertical and a horizontal component. c. have either a vertical or a horizontal component. d. start from rest A baby drops a ball from her hand resting on the serving tray of her high chair. Simultaneously, she knocks another ball from the same tray. Which of the following statements are true? I. Both balls strike the ground at the same time. II. The dropped ball reaches the ground first. III. The knocked ball reaches the ground first. IV. Both balls strike the ground at the same speed. a. I only b. II only c. III only d. I and IV

23 130. A gardener holds the nozzle of a hose constant at a small angle above the horizontal and observes the path of the stream of water coming from the nozzle. If the pressure of the water is increased so that the water leaves the nozzle at a greater speed, a. the height and width of the water s path will increase. b. the height of the water s path will increase but the width of the path will remain the same. c. the width of the water s path will increase but the height will remain the same. d. The height and width of the water s path will remain the same Assuming no air friction and a y = -g, the horizontal displacement of a projectile depends on the a. horizontal component of its initial velocity only. b. vertical component of its initial velocity only. c. vertical component of its initial velocity and its time in flight. d. vertical component and the horizontal component of its initial velocity A volleyball player taps a volleyball well above the net. The ball s speed is least a. just after it is tapped by the player. b. at the highest point of its path. c. just before it strikes the ground. d. when the horizontal and vertical components of its velocity are equal Which of the following is a frame of reference for measuring motion? a. coordinate system b. diagram c. graph d. none of the above The following questions refer to the following situation. In a circus parade, a clown standing on a float moving at a constant forward speed drops a fake dumbbell. A child in the bleachers on the sidewalk observes the dumbbell. Ignore air resistance Who would observe the dumbbell falling straight down? a. the clown only b. the child only c. both the clown and the child d. neither the clown nor the child 135. Who would observe the dumbbell falling backward? a. the clown only b. the child only c. both the clown and the child d. neither the clown nor the child 136. The clown and the child would agree about which of the following observations? a. the time interval for the dumbbell to fall b. the vertical distance the dumbbell falls c. the initial vertical velocity of the dumbbell d. all of the above 137. The dumbbell s motion as described by an acrobat walking in the parade is very similar to the clown s description of the dumbbell s motion. What do you know about the motion of the acrobat? a. The acrobat is at rest with respect to the clown. b. The acrobat is at rest with respect to the float. c. both A and B d. neither A nor B

24 138. If the float has a velocity of +v float with respect to the ground, what is the velocity of the clown as observed by the child? a. 0 b. +v float c. -v float d The velocity of a passenger relative to a boat is -v pb. The velocity of the boat relative to the river it is moving on is +v br. The velocity of the river to the shore is +v rs. What is the velocity of the passenger relative to the shore? Assume the + direction is east for all observers. a. -v pb + v br + v rs b. v pb - (v br + v rs ) c. -(v pb + v br + v rs ) d. v pb + v br + v rs 140. A car traveling at the legal speed limit has velocity +v car with respect to the road. You are in another car traveling in the opposite direction at the legal speed limit with respect to the road. As the first car approaches you, what is its velocity relative to you? a. +v car b. v car c. +2v car d. -2v car 141. Which of the following is a physical quantity that has a magnitude but no direction? a. vector b. scalar c. resultant d. frame of reference 142. Which of the following is an example of a vector quantity? a. velocity b. temperature c. volume d. mass 143. In the figure above, which diagram represents the vector addition, C = A + B? a. I b. II c. III d. IV

25 144. In the figure above, which diagram represents vector subtraction, C = A - B? a. I b. II c. III d. IV 145. Multiplying or dividing vectors by scalars results in a. vectors. b. scalars. c. vectors if multiplied or scalars if divided. d. scalars if multiplied or vectors if divided In a coordinate system, a vector is oriented at angle with respect to the x-axis. The x component of the vector equals the vector s magnitude multiplied by which trigonometric function? a. cos b. cot c. sin d. tan 147. How many displacement vectors shown in the figure above have horizontal components? a. 2 b. 3 c. 4 d. 5

26 Which displacement vectors shown in the figure above have vertical components that are equal? a. d 1 and d 2 b. d 1 and d 3 c. d 2 and d 5 d. d 4 and d 5 A hiker undergoes a displacement of d5 as shown in the figure above. A single displacement that would return the hiker to his starting point would have which of the following sets of components? a. d 5, x; d 5, y b. d 5, x; d 5, y c. d 5, x; d 5, y d. d 5, x; d 5, y 150. Which of the following is an example of projectile motion? a. a jet lifting off a runway b. a baseball being thrown c. dropping an aluminum can into the recycling bin d. a space shuttle orbiting Earth 151. What is the path of a projectile? a. a wavy line b. a parabola c. a hyperbola d. Projectiles do not follow a predictable path.

27 152. Which of the following exhibits parabolic motion? a. a stone thrown into a lake b. a space shuttle orbiting Earth c. a leaf falling from a tree d. a train moving along a flat track 153. Which of the following does not exhibit parabolic motion? a. a frog jumping from land into water b. a basketball thrown through a hoop c. a flat piece of paper released from a window d. a baseball thrown to home plate 154. At what point of the ball s path shown in the figure above is the vertical component of the ball s velocity zero? a. A b. B c. C d. D 155. A passenger on a bus moving east sees a man standing on a curb.from the passenger s perspective, the man appears to a. stand still. b. move west at a speed that is less than the bus s speed. c. move west at a speed that is equal to the bus s speed. d. move east at a speed that is equal to the bus s speed A piece of chalk is dropped by a teacher walking at a speed of 1.5 m/s. From the teacher s perspective, the chalk appears to fall a. straight down. b. straight down and backward. c. straight down and forward. d. straight backward Identify the following quantities as scalar or vector: the mass of an object, the number of leaves on a tree, wind velocity. a. vector, scalar, scalar b. scalar, scalar, vector c. scalar, vector, scalar d. vector, scalar, vector

28 158. A student walks from the door of the house to the end of the driveway and realizes that he missed the bus. The student runs back to the house, traveling three times as fast. Which of the following is the correct expression for the return velocity if the initial velocity is v student? a. 3v student b. v student c. v student d. 3v student 159. An ant on a picnic table travels cm eastward, then 25 cm northward, and finally 15 cm westward. What is the magnitude of the ant s displacement relative to its original position? a. 70 cm b. 57 cm c. 52 cm d. 29 cm 160. In a coordinate system, the magnitude of the x component of a vector and, the angle between the vector and x-axis, are known. The magnitude of the vector equals the x component a. divided by the cosine of. b. divided by the sine of. c. multiplied by the cosine of. d. multiplied by the sine of Find the resultant of these two vectors: units due east and units 30.0 north of west. a. 300 units 29.8 north of west b. 581 units 20.1 north of east c. 546 units 59.3 north of west d. 248 units 53.9 north of west 162. In the figure below, the magnitude of the ball s velocity is least at location a. A b. B c. C d. D

29 163. In the figure below, the horizontal component of the ball s velocity at A is a. zero. b. equal to the vertical component of the ball s velocity at C. c. equal in magnitude but opposite in direction to the horizontal component of the ball s velocity at D. d. equal to the horizontal component of its initial velocity A track star in the long jump goes into the jump at 12 m/s and launches herself at 20.0 above the horizontal. What is the magnitude of her horizontal displacement? (Assume no air resistance and that a y = g = m/s 2.) a. 4.6 m b. 9.2 m c. 13 m d. 15 m 165. A boat travels directly across a river that has a downstream current, v. What is true about the perpendicular components of the boat s velocity? a. One component equals v; the other component equals zero. b. One component is perpendicular to v; the other component equals v. c. One component is perpendicular to v; the other component equals v. d. One component is perpendicular to v; the other component equals zero A jet moving at km/h due east is in a region where the wind is moving at km/h in a direction north of east. What is the speed of the aircraft relative to the ground? a km/h b km/h c km/h d km/h Short Answer 167. Describe a situation that uses the processes of the scientific method. Explain how the scientific processes are used in that situation What is the first step toward simplifying a complicated situation, and what are three ways to summarize a complicated situation? 169. Name at least two advantages for using equations What are order-of-magnitude calculations used to do? 171. Two areas within physics are mechanics and quantum mechanics. Distinguish between these two areas.

30 172. What are the SI base units for length, mass, and time? 173. Convert km to decimeters using scientific notation What must quantities have before they can be added or subtracted? 175. If unexpected results are obtained and confirmed through repeated experiments, why must a model or hypothesis be abandoned or revised? 176. How can only seven basic units serve to express almost any measured quantity? 177. Convert 1 m to meters using scientific notation Why do calculators often exaggerate the precision of a final result? 179. How many significant figures does mg have? 180. What is the name of the length of the straight line drawn from an object s initial position to the object s final position? 181. Construct a graph of position versus time for the motion of a dog, using the data in the table below. Explain how the graph indicates that the dog is moving at a constant speed A horse trots past a fencepost located 12 m to the left of a gatepost. It then passes another fencepost located 24 m to the right of the gatepost 11 s later. What is the average velocity of the horse? 183. A rock is thrown downward from the top of a cliff with an initial speed of 12 m/s. If the rock hits the ground after 2.0 s, what is the height of the cliff? (Disregard air resistance. a 5 2g m/s 2.) The graph below shows the motion of a dog pacing along a fence. Refer to the graph to answer the following questions.

31 184. Describe the dog s motion when it is at 1.0 m What is the dog s average velocity for total displacement? The following questions refer to the following velocity-time graph of a jogger. The positive direction is away from the jogger s home Rank the four displacements for the time intervals CD, DE, EF, and FG in decreasing order. Explain your answer A cat walking at 0.25 m/s sees a mouse and accelerates uniformly at 0.40 m/s 2 for 3.0 s. What is the cat s displacement during this time? 188. How do significant figures indicate a measurement s precision? 189. Calculate the area of a room whose length is m and width is 8.7 m. Express your answer in scientific notation and with the correct number of significant digits A juggler throws a ball vertically upward well above his reach. Sketch a graph of the ball s speed versus time. Show the motion of the ball from the moment it leaves the juggler s hand to the moment the juggler catches it. Assume no air resistance and that the ball is in free fall.

32 191. A climber throws a rope with a velocity of 3.0 m/s downward to another climber 4.0 m directly below. What is the rope s velocity when it reached the lower climber? Assume no air resistance and that a 5 2g = m/s Distinguish between the displacement of a traveler who takes a train from New York to Boston and the displacement of a traveler who flies from Boston to New York. Be sure to compare the magnitudes of the displacements If a runner moves from a positive position to a negative position, explain if the runner s displacement is negative or positive Explain how a dog that has moved can have a displacement of zero Why is the direction of free-fall acceleration usually negative? 196. What is the major difference between a vector quantity and a scalar quantity? 197. A bicycle courier accepts a package and bikes 3 blocks east to the intersection of the street shown on the address label. Encountering road construction, the courier detours by continuing one block east, one block north, and one block west. The courier then bikes two blocks north to the address. What is the resultant displacement of the courier? Use the graphical method What must you do to non-perpendicular vectors before you can use the Pythagorean theorem to calculate the resultant of the vectors? 199. In a blinding blizzard, a reindeer trudges 310 m 45 east of south across the tundra. How far south does the reindeer move? 200. Explain how a projectile can have a horizontal displacement even though its vertical displacement is zero In a movie production, a stunt person must leap from a balcony of one building to a balcony 3.0 m lower on another building. If the buildings are 2.0 m apart, what is the minimum horizontal velocity the stunt person must have to accomplish the jump? Assume no air resistance and that a y = -g = m/s The figure below shows the motion, as seen by a stationary observer, of a stunt dummy (the black circle) as it dropped from a plane during the filming of a movie. Another plane, flying at the same velocity and altitude as the first plane, carries a camera that is filming the drop. If the camera is accidentally dropped at the moment the dummy is dropped, describe the camera s recording of the dummy s motion during its fall A duck maintains a constant swimming speed of 0.50 m/s relative to the water. As it swims across a creek that has a constant downstream current of 0.30 m/s, a naturalist sitting on the bank observes its motion. What is the duck s speed as observed by the naturalist? 204. Is distance or displacement a vector quantity? 205. The equation D = is valid only if x and y are magnitudes of vectors that have what orientation with respect to each other?

33 206. A stone is thrown at an angle of 30.0 above the horizontal from the top edge of a cliff with an initial speed of 12 m/s. A stopwatch measures the stone s trajectory time from the top of the cliff to the bottom at 5.6 s. What is the height of the cliff? (Assume no air resistance and that a y = g = 9.81 m/s 2.) 207. A small airplane flies at a velocity of 145 km/h toward the south as observed by a person on the ground. The airplane pilot measures an air velocity of 172 km/h south. What is the velocity of the wind that affects the plane? 208. Briefly explain the triangle (or polygon) method of addition If the magnitude of a component vector equals the magnitude of the vector, then what is the magnitude of the other component vector? 210. How can you use the Pythagorean theorem to add two vectors that are not perpendicular? 211. Briefly explain why a basketball being thrown toward a hoop is considered projectile motion. Problem 212. Calculate the following, expressing the answer in scientific notation with the correct number of significant figures: ( x 10-3 ) The radius of Earth is m. The average Earth-sun distance is m. How many Earths would fit between Earth and the sun if they are separated by their average distance? Use an order-of-magnitude calculation to estimate this number. Then, determine an exact answer and express it in scientific notation with the correct number of significant digits Trial 1 Trial 2 Trial 3 Trial s 20.5 C 21.3 C 20.8 C 21.0 C 5.0 s 21.0 C 22.9 C 21.4 C 21.7 C 10.0 s 21.6 C 24.1 C 22.0 C 22.3 C 15.0 s 22.2 C 26.8 C 22.7 C 22.8 C 20.0 s 23.0 C 28.2 C 23.2 C 23.3 C Four trials of a chemical reaction were completed, and the change in temperature T was measured every five seconds. Based on the data in the table above, answer the following questions. Are there any unexpected or unusual results? Explain your answer. What is the general relationship between temperature and time? Disregarding any trial(s) with unexpected results, express this relationship in the form of a general equation A biker travels at an average speed of 18 km/h along a 0.30-km straight segment of a bike path. How much time does the biker take to travel this segment? 216. A hiker travels south along a straight path for 1.5 h with an average speed of 0.75 km/h and then travels north for 2.5 h with an average speed of 0.90 km/h. What is the hiker s displacement for the total trip? 217. A skater glides off a frozen pond onto a patch of ground at a speed of 1.8 m/s. Here she is slowed at a constant rate of 3.00 m/s 2. How fast is the skater moving when she has slid 0.37 m across the ground?

34 218. Human reaction time is usually about 0.20 s. If your lab partner holds a ruler between your finger and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it? (Disregard air resistance. a = g = 9.81 m/s 2.) 219. A pair of glasses are dropped from the top of a 32.0 m high stadium. A pen is dropped 2.00 s later. How high above the ground is the pen when the glasses hit the ground? (Disregard air resistance. a = g = 9.81 m/s 2.) 220. A cave explorer travels 3.0 m eastward, then 2.5 m northward, and finally 15.0 m westward. Use the graphical method to find the magnitude of the net displacement A dog walks 28 steps north and then walks 55 steps west to bury a bone. If the dog walks back to the starting point in a straight line, how many steps will the dog take? Use the graphical method to find the magnitude of the net displacement A quarterback takes the ball from the line of scrimmage and runs backward for m then sideways parallel to the line of scrimmage for 15 m. The ball is thrown forward m perpendicular to the line of scrimmage. The receiver is tackled immediately. How far is the football displaced from its original position? 223. Vector A is 3.2 m in length and points along the positive y-axis. Vector B is 4.6 m in length and points along a direction 195 counterclockwise from the positive x-axis. What is the magnitude of the resultant when vectors A and B are added? 224. A model rocket flies horizontally off the edge of a cliff at a velocity of 50.0m/s. If the canyon below is m deep, how far from the edge of the cliff does the model rocket land? (a y = g = 9.81 m/s 2 ) 225. A boat moves at 10.0 m/s relative to the water. If the boat is in a river where the current is 2.00 m/s, how long does it take the boat to make a complete round trip of m upstream followed by m downstream.