Exam (elaborations) TEST BANK FOR_SERWAY AND VUILLE’S_COLLEGE PHYSICS NINTH EDITION, VOLUMES 1 & 2

Exam (elaborations) TEST BANK FOR_SERWAY AND VUILLE’S_COLLEGE PHYSICS NINTH EDITION, VOLUMES 1 & 2 Chapter 1—Introduction MULTIPLE CHOICE 1. Since 1983 the standard meter has been defined in terms of which of the following? a. specific alloy bar housed at Sevres, France b. wavelength of light emitted by krypton-86 c. distance from the Earth's equator to the North Pole d. the distance light travels in a certain fraction of a second ANS: D PTS: 1 DIF: 1 TOP: 1.1 Standards of Length, Mass, and Time 2. Since 1967 the standard definition for the second has been based on which of the following? a. characteristic frequency of the cesium-133 atom b. average solar day c. sidereal day d. Greenwich Civil Time ANS: A PTS: 1 DIF: 1 TOP: 1.1 Standards of Length, Mass, and Time 3. In mechanics, physicists use three basic quantities to derive additional quantities. Mass is one of the three quantities. What are the other two? a. length and force b. power and force c. length and time d. force and time ANS: C PTS: 1 DIF: 1 TOP: 1.1 Standards of Length, Mass, and Time 4. The prefixes which are abbreviated p, n, and G represent which of the following? a. 10-2, 10-6, and 1015 b. 10-9, 106, and 1010 c. 10-12, 10-9, and 109 d. 10-15, 10-6, and 1012 ANS: C PTS: 1 DIF: 1 TOP: 1.1 Standards of Length, Mass, and Time 5. The ratio M/m of the prefixes M and m has what value? a. 103 b. 106 c. 109 d. 1018 ANS: C PTS: 1 DIF: 2 TOP: 1.1 Standards of Length, Mass, and Time 6. One year is about ____ seconds while one day is exactly ____ seconds. a. 3.16 ´ 107, 86 400 b. 5.26 ´ 105, 86 400 c. 3.16 ´ 107, 8 640 d. 1.04 ´ 106, 36 000 ANS: A PTS: 1 DIF: 2 TOP: 1.1 Standards of Length, Mass, and Time 7. The nuclei of atoms contain a. electrons only. b. neutrons only. c. protons and electrons. d. protons and neutrons. ANS: D PTS: 1 DIF: 1 TOP: 1.2 The Building Blocks of Matter 8. When was the existence of the neutron confirmed? a. in ancient times b. in 1895 c. in 1932 d. in 1969 ANS: C PTS: 1 DIF: 1 TOP: 1.2 The Building Blocks of Matter 9. The proton contains which of the following combination of quarks? a. two up quarks and one down quark b. one up quark and two down quarks c. one top quark and two bottom quarks d. two top quarks and one bottom quark ANS: A PTS: 1 DIF: 2 TOP: 1.2 The Building Blocks of Matter 10. Which formula is dimensionally consistent with an expression yielding a value for velocity? (a is acceleration, x is distance, and t is time) a. v/t2 b. vx2 c. v2/t d. at ANS: D PTS: 1 DIF: 1 TOP: 1.3 Dimensional Analysis 11. Which expression is dimensionally consistent with an expression that would yield a value for time-1? (v is velocity, x is distance, and t is time) a. v/x b. v2/x c. x/t d. v2t ANS: A PTS: 1 DIF: 1 TOP: 1.3 Dimensional Analysis 12. If the displacement of an object, x, is related to velocity, v, according to the relation x = Av, the constant, A, has the dimension of which of the following? a. acceleration b. length c. time d. area ANS: C PTS: 1 DIF: 1 TOP: 1.3 Dimensional Analysis 13. The speed of a boat is often given in knots. If a speed of 5 knots were expressed in the SI system of units, the units would be: a. m. b. s. c. m/s. d. kg/s. ANS: C PTS: 1 DIF: 1 TOP: 1.3 Dimensional Analysis 14. If a is acceleration, v is velocity, x is position, and t is time, then which equation is not dimensionally correct? a. t = x/v b. a = v2/x c. v = a/t d. t2 = 2x/a ANS: C PTS: 1 DIF: 1 TOP: 1.3 Dimensional Analysis 15. Suppose an equation relating position, x, to time, t, is given by x = b t3 + c t4, where b and c are constants. The dimensions of b and c are respectively: a. T3, T4. b. 1/T3, 1/T4. c. L/T3, L/T4. d. L2×T3, L2×T4. ANS: C PTS: 1 DIF: 2 TOP: 1.3 Dimensional Analysis 16. Areas always have dimensions ____ while volumes always have dimensions ____. a. m2, m3 b. L2, L3 c. Both a and b are correct. d. No answer is correct because of the "always." ANS: B PTS: 1 DIF: 1 TOP: 1.3 Dimensional Analysis 17. Which one of the choices below represents the preferred practice regarding significant figures when adding the following: 12.4 + 11 + 67.37 + 4.201? a. 94.971 b. 94.97 c. 95.0 d. 95 ANS: D PTS: 1 DIF: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures 18. Which one of the choices below represents the preferred practice regarding significant figures when multiplying the following: 10.5 ´ 8.8 ´ 3.14? a. 290 b. 290.136 c. 290.1 d. 300 ANS: A PTS: 1 DIF: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures 19. Calculate (0.82 + 0.042) ´ (4.4 ´ 103), keeping only significant figures. a. 3 800 b. 3 784 c. 3 793 d. 3 520 ANS: A PTS: 1 DIF: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures 20. The length and width of a standard sheet of paper is measured, and then the area is found by calculation to be 93.50 in2. The number of significant figures in the width measurement must be at least: a. 1. b. 2. c. 3. d. 4. ANS: D PTS: 1 DIF: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures 21. The number 0.000 17 has how many significant figures? a. 2 b. 3 c. 5 d. 6 ANS: A PTS: 1 DIF: 2 TOP: 1.4 Uncertainty in Measurement and Significant Figures 22. Multiplying a 2 significant figure number by a 3 significant figure number and then dividing the product by a six significant figure number yields a number with how many significant figures? a. 5/6 b. 1 c. 2 d. 11 ANS: C PTS: 1 DIF: 3 TOP: 1.4 Uncertainty in Measurement and Significant Figures 23. Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 6 and 7 cm, how many significant figures will result if you only use the part of the meter stick between the 1-cm and 9-cm positions? a. 2 b. 3 c. 4 d. more than 4 ANS: B PTS: 1 DIF: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures 24. Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 6 and 7 cm, how many significant figures will result if you only use the part of the meter stick between the 82- and 95-cm positions? a. 2 b. 3 c. 4 d. more than 4 ANS: B PTS: 1 DIF: 2 TOP: 1.4 Uncertainty in Measurement and Significant Figures 25. Assume when using a meter stick measuring can be done so that the last significant figure is in the tenth of a millimeter digit. If you are measuring an object with length between 25 and 57 cm, how many significant figures will result if you only use the part of the meter stick between the 2- and 95-cm positions? a. 2 b. 3 c. 4 d. more than 4 ANS: C PTS: 1 DIF: 2 TOP: 1.4 Uncertainty in Measurement and Significant Figures 26. How many significant figures does the number 1 700 have? a. 2 b. 3 c. 4 d. One cannot tell with certainty when the number is written in the given form, but it will be one of the other given answers. ANS: D PTS: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures 27. In the text are the following conversion factors: i. 1 mi = 1 609 m ii. 1 m = 39.37 in. iii. 1 ft = 30.48 cm iv. 1 in. = 2.54 cm The 1 on the left hand side is assumed to have the same number of significant figures as the number on the right hand side of each of these equations. However, 2 of these conversion factors are exact, and this means they have the equivalent of an unlimited number of significant figures when used in calculations. Which 2 are the exact conversion factors? a. i and ii b. i and iii c. ii and iii d. iii and iv ANS: D PTS: 1 TOP: 1.4 Uncertainty in Measurement and Significant Figures | 1.5 Conversion of Units 28. On planet Q the standard unit of volume is called the guppy. Space travelers from Earth have determined that one liter = 38.2 guppies. How many guppies are in 150 liters? a. 5 730 guppies b. 0.255 guppies c. 3.93 guppies d. 188 guppies ANS: A PTS: 1 DIF: 1 TOP: 1.5 Conversion of Units 29. On planet Z, the standard unit of length is the foose. Ann the Astronaut is 5.90 feet tall on earth. She lands on planet Z and is measured to be 94 foosi tall. Her partner Rachael is 88 foosi tall. How tall is Rachael on Earth? a. 5.2 feet b. 5.5 feet c. 5.8 feet d. 6.3 feet ANS: B PTS: 1 DIF: 2 TOP: 1.5 Conversion of Units 30. A furlong is a distance of 220 yards. A fortnight is a time period of two weeks. A race horse is running at a speed of 5.00 yards per second. What is his speed in furlongs per fortnight? a. 27 500 furlongs/fortnight b. 13 700 furlongs/fortnight c. 6 220 furlongs/fortnight d. 2 750 furlongs/fortnight ANS: A PTS: 1 DIF: 2 TOP: 1.5 Conversion of Units 31. A cereal box has the dimensions of 0.19 m ´ 0.28 m ´ 0.070 m. If there are 3.28 feet per meter, then what is the volume of the box in cubic feet? a. 0.13 cubic feet b. 0.040 cubic feet c. 0.012 cubic feet d. 0.003 7 cubic feet ANS: A PTS: 1 DIF: 1 TOP: 1.5 Conversion of Units 32. The distance to the Andromeda Galaxy is estimated at about 2 ´ 106 light years. A light year is the distance traveled by light in one year; if the speed of light is 3 ´ 108 m/s, about how far is it from our galaxy to Andromeda? (1 year = 3.15 ´ 107 s) a. 10 ´ 1015 m b. 1 ´ 1018 m c. 2 ´ 1022 m d. 6 ´ 1012 m ANS: C PTS: 1 DIF: 2 TOP: 1.5 Conversion of Units 33. A cement truck can pour 20 cubic yards of cement per hour. Express this in ft3/min. a. 1/3 ft3/min b. 1.0 ft3/min c. 3 ft3/min d. 9 ft3/min ANS: D PTS: 1 DIF: 1 TOP: 1.5 Conversion of Units 34. Water flows into a swimming pool at the rate of 8.0 gal/min. The pool is 16 ft wide, 32 ft long and 8.0 ft deep. How long does it take to fill? (1 U.S. gallon = 231 cubic inches) a. 32 hours b. 64 hours c. 48 hours d. 24 hours ANS: B PTS: 1 DIF: 2 TOP: 1.5 Conversion of Units 35. When NASA was communicating with astronauts on the moon, the time from sending on the Earth to receiving on the moon was 1.28 s. Find the distance from Earth to the moon. (The speed of radio waves is 3.00 ´ 108 m/s.) a. 240 000 km b. 384 000 km c. 480 000 km d. 768 000 km ANS: B PTS: 1 DIF: 2 TOP: 1.5 Conversion of Units 36. The mass of the sun is 2.0 ´ 1030 kg, and the mass of a hydrogen atom is 1.67 ´ 10-27 kg. If we assume that the sun is mostly composed of hydrogen, how many atoms are there in the sun? a. 1.2 ´ 1056 atoms b. 3.4 ´ 1056 atoms c. 1.2 ´ 1057 atoms d. 2.4 ´ 1057 atoms ANS: C PTS: 1 DIF: 2 TOP: 1.5 Conversion of Units 37. The information on a one-gallon paint can is that the coverage, when properly applied, is 450 ft2. One gallon is 231 in3. What is the average thickness of the paint in such an application? a. 0.003 6 in b. 0.009 0 in c. 0.043 in d. 0.051 in ANS: A PTS: 1 DIF: 3 TOP: 1.5 Conversion of Units 38. Assume everyone in the United States consumes one soft drink in an aluminum can every two days. If there are 270 million Americans, how many tons of aluminum need to be recycled each year if each can weighs 1/16 pound and one ton = 2000 pounds? a. 750 000 tons b. 1.5 million tons c. 1.75 million tons d. 3 million tons ANS: B PTS: 1 DIF: 2 TOP: 1.6 Estimates and Order-of-Magnitude Calculations 39. A physics class in a large lecture hall has 150 students. The total mass of the students is about ____ kg. a. 102 b. 103 c. 104 d. 105 ANS: C PTS: 1 DIF: 2 TOP: 1.6 Estimates and Order-of-Magnitude Calculations 40. An apartment has 1100 ft2 of floor space. What is the approximate volume of the apartment? a. 103 ft3 b. 104 ft3 c. 105 ft3 d. 106 ft3 ANS: B PTS: 1 DIF: 2 TOP: 1.6 Estimates and Order-of-Magnitude Calculations 41. Which point is nearest the x-axis? a. (-3, 4) b. (4, 5) c. (-5, 3) d. (5, -2) ANS: D PTS: 1 DIF: 2 TOP: 1.7 Coordinate Systems 42. Each edge of a cube has a length of 25.4 cm. What is the length of a diagonal of the cube going through the center of the cube? a. 25.4 in b. 17.3 in c. 14.4 in d. 10.0 in ANS: B PTS: 1 DIF: 3 TOP: 1.7 Coordinate Systems 43. If point A is located at coordinates (5, 3) and point B is located at coordinates (-3, 9), what is the distance from A to B if the units of the coordinated system are meters? a. 14 m b. 10 m c. 8 m d. 17 m ANS: B PTS: 1 DIF: 2 TOP: 1.7 Coordinate Systems 44. A high fountain of water is in the center of a circular pool of water. You walk the circumference of the pool and measure it to be 150 meters. You then stand at the edge of the pool and use a protractor to gauge the angle of elevation of the top of the fountain. It is 55°. How high is the fountain? a. 17 m b. 23 m c. 29 m d. 34 m ANS: D PTS: 1 DIF: 3 TOP: 1.8 Trigonometry 45. A right triangle has sides 5.0 m, 12 m, and 13 m. The smallest angle of this triangle is nearest: a. 21°. b. 23°. c. 43°. d. Not attainable since this is not a right triangle. ANS: B PTS: 1 DIF: 2 TOP: 1.8 Trigonometry 46. If j = 90° - q, what is the value of sin2 j + sin2 q? a. 0 b. 1 c. -1 d. The answer depends on q. ANS: B PTS: 1 DIF: 2 TOP: 1.8 Trigonometry 47. A triangle has sides of length 7.0 cm and 25 cm. If the triangle is a right triangle, which of the following could be the length of the third side? a. 18 cm b. 24 cm c. 27 cm d. 32 cm ANS: B PTS: 1 DIF: 2 TOP: 1.8 Trigonometry 48. A train slowly climbs a 500-m mountain track which is at an angle of 10.0° with respect to the horizontal. How much altitude does it gain? a. 86.8 m b. 88.2 m c. 341 m d. 492 m ANS: A PTS: 1 DIF: 2 TOP: 1.8 Trigonometry 49. Note the expression: y = x2. Which statement is most consistent with this expression? a. If y doubles, then x quadruples. b. y is greater than x. c. If x doubles, then y doubles. d. If x doubles, then y quadruples. ANS: D PTS: 1 DIF: 1 TOP: Additional Problems 50. Note the expression: y = A/x3. Which statement is most consistent with this expression? a. y is less than A. b. If x is halved, y is multiplied by eight. c. If x is doubled, y is multiplied by a factor of 8. d. y is greater than x. ANS: B PTS: 1 DIF: 1 TOP: Additional Problems 51. For which of the values below is x > x3? a. x = -1.5 b. x = 0 c. x = 1.0 d. x = 1.5 ANS: A PTS: 1 DIF: 1 TOP: Additional Problems 52. Modern electroplaters can cover a surface area of 60.0 m2 with one troy ounce of gold (volume = 1.611 cm3). What is the thickness of the electroplated gold? a. 2.68 ´ 10-8 m b. 1.34 ´ 10-9 m c. 1.67 ´ 10-6 m d. 3.33 ´ 10-7 m ANS: A PTS: 1 DIF: 2 TOP: Additional Problems 53. The basic function of an automobile's carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assume that 30 cm3 of gasoline is atomized into N spherical droplets. Each droplet has a radius of 2.0 ´ 10-5 m. Find the total surface area of these N spherical droplets. a. 2 100 cm2 b. 15 000 cm2 c. 18 000 cm2 d. 45 000 cm2 ANS: D PTS: 1 DIF: 3 TOP: Additional Problems 54. A circle has an area of 2.0 m2. A second circle has double the radius of the first. The area of the second circle is ____ times that of the first. a. 0.50 b. 2.0 c. 4.0 d. 8.0 ANS: C PTS: 1 DIF: 2 TOP: Additional Problems 55. Doubling the radius of a sphere results in increasing its volume by a factor of a. 2 b. 4 c. 8 d. 8 p ANS: C PTS: 1 DIF: 2 TOP: Additional Problems 56. A room in a house has a floor area of 120 ft2. Which of the following is most likely the approximate volume of the room? a. 3 m3 b. 30 m3 c. 300 m3 d. 3 000 m3 ANS: B PTS: 1 DIF: 2 TOP: Conceptual Problems 57. When SI units are plugged into an equation, it is found that the units balance. Which of the following can we expect to be true for this equation? a. The equation will be dimensionally correct. b. The equation will be dimensionally correct except sometimes in cases when the right hand side of the equation has more than one term. c. The equation will not be dimensionally correct. d. All constants of proportionality will be correct. ANS: A PTS: 1 DIF: 1 TOP: Conceptual Problems 58. How long has it been that scientists have accepted that the nucleus of the atom consists of neutrons and protons? Think of your answers in terms of order of magnitude. a. about a decade b. about a century c. about a thousand years d. since Aristotle ANS: B PTS: 1 DIF: 1 TOP: Conceptual Problems 59. Consider the sine of any angle between 30° and 40°. If the angle were doubled, what would happen to the sine of the angle? a. It would double. b. It would more than double. c. It would increase but be less than double. d. In different cases, it could do any of the above. ANS: C PTS: 1 DIF: 2 TOP: Conceptual Problems 60. There are other ways of expressing uncertainty besides significant figures. For example, suppose a quantity is known to have a value between 20.4 and 20.0, and our best estimate of the value is midrange at 20.2. We could write the number as 20.2 +/- 0.2 and say that the number has a 1% uncertainty. We would also say it has 3 significant figures. If we square a number with 1% uncertainty (i.e., 2 parts in about 200) and 3 significant figures, what results? a. A number with 1% uncertainty and 3 significant figures. b. A number with 2% uncertainty and 3 significant figures. c. A number with 2% uncertainty and 2 significant figures. d. A number with 1% uncertainty and 2 significant figures. ANS: B PTS: 1 DIF: 2 TOP: Conceptual Problems Chapter 2—Motion in One Dimension MULTIPLE CHOICE 1. A change in a physical quantity w having initial value wi and final value wf is given by which of the following? a. wi - wf b. wf - wi c. (wf + wi)/2 d. none of the above ANS: B PTS: 1 DIF: 1 TOP: 2.1 Displacement 2. Displacement is which of the following types of quantities? a. vector b. scalar c. magnitude d. dimensional ANS: A PTS: 1 DIF: 1 TOP: 2.1 Displacement 3. A truck moves 70 m east, then moves 120 m west, and finally moves east again a distance of 90 m. If east is chosen as the positive direction, what is the truck's resultant displacement? a. 40 m b. -40 m c. 280 m d. -280 m ANS: A PTS: 1 DIF: 2 TOP: 2.1 Displacement 4. Which of the following is not a vector quantity? a. temperature b. velocity c. acceleration d. displacement ANS: A PTS: 1 DIF: 1 TOP: 2.1 Displacement 5. In one-dimensional motion, the average speed of an object that moves from one place to another and then back to its original place has which of the following properties? a. It is positive. b. It is negative. c. It is zero. d. It can be positive, negative, or zero. ANS: A PTS: 1 DIF: 2 TOP: 2.2 Velocity 6. In one-dimensional motion where the direction is indicated by a plus or minus sign, the average velocity of an object has which of the following properties? a. It is positive. b. It is negative. c. It is zero. d. It can be positive, negative, or zero. ANS: D PTS: 1 DIF: 1 TOP: 2.2 Velocity 7. An object moves 20 m east in 30 s and then returns to its starting point taking an additional 50 s. If west is chosen as the positive direction, what is the sign associated with the average velocity of the object? a. + b. - c. 0 (no sign) d. any of the above ANS: C PTS: 1 DIF: 1 TOP: 2.2 Velocity 8. An object moves 20 m east in 30 s and then returns to its starting point taking an additional 50 s. If west is chosen as the positive direction, what is the average speed of the object? a. 0.50 m/s b. -0.50 m/s c. 0.73 m/s d. 0 m/s ANS: A PTS: 1 DIF: 2 TOP: 2.2 Velocity 9. A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the average velocity? a. 1.7 m/s b. 2.5 m/s c. 3.4 m/s d. zero ANS: B PTS: 1 DIF: 1 TOP: 2.2 Velocity 10. A cheetah can run at approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey? a. 12.6 s b. 25.2 s c. 6.30 s d. 10.7 s ANS: A PTS: 1 DIF: 2 TOP: 2.2 Velocity 11. A cheetah can maintain its maximum speed of 100 km/hr for 30.0 seconds. What minimum distance must a gazelle running 80.0 km/hr be ahead of the cheetah to escape? a. 100 m b. 167 m c. 70.0 m d. 83.0 m ANS: B PTS: 1 DIF: 3 TOP: 2.2 Velocity 12. Jeff throws a ball straight up. For which situation is the vertical velocity zero? a. on the way up b. at the top c. on the way back down d. none of the above ANS: B PTS: 1 DIF: 1 TOP: 2.2 Velocity 13. A railroad train travels forward along a straight track at 80.0 m/s for 1 000 m and then travels at 50.0 m/s for the next 1 000 m. What is the average velocity? a. 65.0 m/s b. 61.5 m/s c. 63.7 m/s d. 70.0 m/s ANS: B PTS: 1 DIF: 2 TOP: 2.2 Velocity 14. The distance of the Earth from the sun is miles. If there are 3.15 ´ 107 s in one year, find the speed of the Earth in its orbit about the sun. a. 9.28 miles/s b. 18.6 miles/s c. 27.9 miles/s d. 37.2 miles/s ANS: B PTS: 1 DIF: 2 TOP: 2.2 Velocity 15. A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and back down to the starting position), its average velocity is: a. 19.6 m/s. b. 9.80 m/s. c. 4.90 m/s. d. not given. ANS: D PTS: 1 DIF: 2 TOP: 2.2 Velocity 16. Changing the positive direction in a reference frame to the opposite direction does not change the sign of which of the following quantities? a. velocity b. average velocity c. speed d. displacement ANS: C PTS: 1 DIF: 1 TOP: 2.2 Velocity 17. On a position versus time graph, the slope of the straight line joining two points on the plotted curve that are separated in time by the interval Dt, is which of the following quantities? a. average steepness b. average velocity c. instantaneous velocity d. average acceleration ANS: B PTS: 1 DIF: 1 TOP: 2.2 Velocity 18. Consider the magnitude of the average speed, , and the magnitude of the average velocity, , for the same trip. Which of the following is always true? a. b. c. d. none of the above ANS: B PTS: 1 TOP: 2.2 Velocity 19. A European sports car dealer claims that his car will accelerate at a constant rate from rest to 100 km/hr in 8.00 s. If so, what is the acceleration? (Hint: First convert speed to m/s.) a. 3.47 m/s2 b. 6.82 m/s2 c. 11.4 m/s2 d. 17.4 m/s2 ANS: A PTS: 1 DIF: 2 TOP: 2.3 Acceleration 20. A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 100 km/hr in 8.00 s. What is the speed after the first 5.00 s of acceleration? (Hint: First convert the speed to m/s.) a. 34.7 m/s b. 44.4 m/s c. 28.7 m/s d. 17.4 m/s ANS: D PTS: 1 DIF: 2 TOP: 2.3 Acceleration 21. An x vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the velocity of the ball is zero. We can be positive that at t = 5 s, a. the slope of the curve is non-zero. b. the ball has stopped. c. the acceleration is constant. d. the curve is at x = 0, t = 0. ANS: B PTS: 1 DIF: 1 TOP: 2.3 Acceleration 22. A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the acceleration of the ball is zero. We know that at t = 5 s, a. the slope of the curve is non-zero. b. the velocity of the ball is not changing. c. the curve is not crossing the time axis. d. the curve is at v = 0, t = 0. ANS: B PTS: 1 DIF: 1 TOP: 2.3 Acceleration 23. The value of an object's acceleration may be characterized in equivalent words by which of the following? a. displacement b. rate of change of displacement c. velocity d. rate of change of velocity ANS: D PTS: 1 DIF: 1 TOP: 2.3 Acceleration 24. A 50-g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50 ms, what is the average acceleration of the ball during this time interval? a. 13 400 m/s2 b. 6 720 m/s2 c. 857 m/s2 d. 20 m/s2 ANS: A PTS: 1 DIF: 2 TOP: 2.3 Acceleration 25. An object is dropped from a height. Once it is moving, which of the following statements is true, at least at one point? a. Its velocity is more than its acceleration. b. Its velocity is less than its acceleration. c. Its velocity is the same as its acceleration. d. Its velocity is never equal to its acceleration. ANS: D PTS: 1 DIF: 2 TOP: 2.3 Acceleration 26. The slope of the acceleration vs. time curve represents: a. the velocity. b. the rate of change of acceleration. c. the rate of change of displacement. d. the area under the position vs. time curve. ANS: B PTS: 1 DIF: 2 TOP: 2.3 Acceleration 27. A strobe photograph shows equally spaced images of a car moving along a straight road. If the time intervals between images is constant, which of the following cannot be positive? a. the speed of the car b. the average velocity of the car c. the acceleration of the car d. the direction of motion of the car ANS: C PTS: 1 DIF: 2 TOP: 2.4 Motion Diagrams 28. A strobe photograph of a car moving along a straight road shows the interval between each successive image to be diminishing. If the direction of motion of the car is taken as positive, which of the following are negative? a. the speed of the car b. the average velocity of the car c. the average acceleration of the car d. all of the above ANS: C PTS: 1 DIF: 2 TOP: 2.4 Motion Diagrams 29. A ball is pushed with an initial velocity of 4.0 m/s. The ball rolls down a hill with a constant acceleration of 1.6 m/s2. The ball reaches the bottom of the hill in 8.0 s. What is the ball's velocity at the bottom of the hill? a. 10 m/s b. 12 m/s c. 16 m/s d. 17 m/s ANS: D PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 30. A cart is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 2.0 m/s2. What is the magnitude of the cart's displacement during the first 6.0 s of its motion? a. 10 m b. 55 m c. 66 m d. 80 m ANS: C PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 31. A vehicle designed to operate on a drag strip accelerates from zero to 30 m/s while undergoing a straight line path displacement of 45 m. What is the vehicle's acceleration if its value may be assumed to be constant? a. 2.0 m/s2 b. 5.0 m/s2 c. 10 m/s2 d. 15 m/s2 ANS: C PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 32. When a drag strip vehicle reaches a velocity of 60 m/s, it begins a negative acceleration by releasing a drag chute and applying its brakes. While reducing its velocity back to zero, its acceleration along a straight line path is a constant -7.5 m/s2. What displacement does it undergo during this deceleration period? a. 40 m b. 80 m c. 160 m d. 240 m ANS: D PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 33. A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is the final velocity after 11 s? a. 1.8 m/s b. 3.2 m/s c. 5.1 m/s d. zero ANS: C PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 34. A bird, accelerating from rest at a constant rate, experiences a displacement of 28 m in 11 s. What is its acceleration? a. 0.21 m/s2 b. 0.46 m/s2 c. 0.64 m/s2 d. 0.78 m/s2 ANS: B PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 35. A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 100 km/hr in 8.00 s. What distance will the sports car travel during the 8 s acceleration period? (Hint: First convert speed to m/s.) a. 55.5 m b. 77.7 m c. 111 m d. 222 m ANS: C PTS: 1 DIF: 2 TOP: 2.5 One-Dimensional Motion with Constant Acceleration 36. Norma releases a bowling ball from rest; it rolls down a ramp with constant acceleration. After half a second it has traveled 0.75 m. How far has it traveled after two seconds? a. 1.2 m b. 4.7 m c. 9.0 m d. 12 m ANS: D PTS: 1 DIF: