TEST BANK
TEST BANK
Chapter: 1. Introduction, Measurement, Estimating Chapter: 2. Describing Motion: Kinematics in One Dimension Chapter: 3. Kinematics in Two Dimensions; Vectors Chapter: 4. Dynamics: Newton's Laws of Motion Chapter: 5. Circular Motion; Gravitation Chapter: 6. Work and Energy Chapter: 7. Linear Momentum Chapter: 8. Rotational Motion Chapter: 9. Static Equilibrium; Elasticity and Fracture Chapter: 10. Fluids Chapter: 11. Oscillations and Waves Chapter: 12. Sound Chapter: 13. Temperature and Kinetic Theory Chapter: 14. Heat Chapter: 15. The Laws of Thermodynamics Chapter: 16. Electric Charge and Electric Field Chapter: 17. Electric Potential Chapter: 18. Electric Currents Chapter: 19. DC Circuits Chapter: 20. Magnetism Chapter: 21. Electromagnetic Induction and Faraday's Law Chapter: 22. Electromagnetic Waves Chapter: 23. Light: Geometric Optics Chapter: 24. The Wave Nature of Light Chapter: 25. Optical Instruments Chapter: 26. The Special Theory of Relativity Chapter: 27. Early Quantum Theory and Models of the Atom Chapter: 28. Quantum Mechanics of Atoms Chapter: 29. Molecules and Solids Chapter: 30. Nuclear Physics and Radioactivity
Chapter: 31. Nuclear Energy; Effects and Uses of Radiation Chapter: 32. Elementary Particles Chapter: 33. Astrophysics and Cosmology
Exam Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The current definition of the standard meter of length is based on A) the distance between the earth and the sun. B) the distance traveled by light in a vacuum. C) the length of a particular object kept in France. D) the distance between the earth's equator and north pole.
1)
Answer: B 2) The current definition of the standard second of time is based on A) the frequency of radiation emitted by cesium atoms. B) the oscillation of a particular pendulum kept in France. C) the duration of one year. D) the earth's rotation rate.
2)
Answer: A 3) The current definition of the standard kilogram of mass is based on A) the mass of the earth. B) the mass of the sun. C) the mass of a cesium-133 atom. D) the mass a particular object kept in France.
3)
Answer: D 4) If a woman weighs 125 lb, her mass expressed in kilograms is x kg, where x is A) greater than 125. B) less than 125.
4)
Answer: B 5) If a tree is 15 m tall, its height expressed in feet is x ft, where x is A) greater than 15. B) less than 15.
5)
Answer: A 6) If a flower is 6.5 cm wide, its width expressed in millimeters is x mm, where x is A) greater than 6.5. B) less than 6.5.
6)
Answer: A 7) If an operatic aria lasts for 5.75 min, its length expressed in seconds is x s, where x is A) greater than 5.75. B) less than 5.75.
7)
Answer: A 8) Scientists use the metric system chiefly because it is more accurate than the English system. A) True B) False
8)
Answer: B 9) When adding two numbers, the number of significant figures in the sum is equal to the number of significant figures in the least accurate of the numbers being added. A) True B) False Answer: B 1
9)
10) When determining the number of significant figures in a number, zeroes to the left of the decimal point are never counted. A) True B) False
10)
Answer: B 11) Convert 1.2 × 10-3 to decimal notation. A) 1.200 B) 0.1200
C) 0.0120
D) 0.0012
E) 0.00012
11)
Answer: D 12) Write out the number 7.35 × 10-5 in full with a decimal point and correct number of zeros. A) 0.00000735 B) 0.0000735 C) 0.000735 D) 0.00735 E) 0.0735
12)
Answer: B 13) 0.0001776 can also be expressed as A) 1.776 × 10-3. B) 1.776 × 10-4. C) 17.72 × 104 . D) 1772 × 105 .
13)
E) 177.2 × 107 .
Answer: B 14) 0.00325 × 10-8 cm can also be expressed in mm as A) 3.25 × 10-12 mm. B) 3.25 × 10-11 mm. C) 3.25 × 10-10 mm. D) 3.25 × 10-9 mm. E) 3.25 × 10-8 mm.
14)
Answer: C 15) If, in a parallel universe, figures. A) 3.141
has the value 3.14149, express
B) 3.142
in that universe to four significant
C) 3.1415
15)
D) 3.1414
Answer: A 16) The number 0.003010 has A) 7 significant figures. C) 4 significant figures.
16)
B) 6 significant figures. D) 2 significant figures.
Answer: C 17) What is
0.674 to the proper number of significant figures? 0.74
A) 0.9108
B) 0.91
C) 0.9
Answer: B
2
17) D) 0.911
18) What is the value of (8.104) 2 , written with the correct number of significant figures? A) 206.324 B) 206.323 C) 206.3 D) 206 E) 200
18)
Answer: C 19) What is the sum of 1123 and 10.3 written with the correct number of significant figures? A) 1.1 × 103 B) 1.13 × 103 C) 1133 D) 1133.3000 E) 1133.3
19)
Answer: C 20) What is the sum of 1.53 + 2.786 + 3.3 written with the correct number of significant figures? A) 8 B) 7.6 C) 7.62 D) 7.616 E) 7.6160
20)
Answer: B 21) What is the difference between 103.5 and 102.24 written with the correct number of significant figures? A) 1 B) 1.3 C) 1.26 D) 1.260 E) 1.2600
21)
Answer: B 22) What is the product of 11.24 and 1.95 written with the correct number of significant figures? A) 22 B) 21.9 C) 21.92 D) 21.918 E) 21.9180
22)
Answer: B 23) What is the result of 1.58 ÷ 3.793 written with the correct number of significant figures? A) 4.2 × 10-1
23)
B) 4.1656 × 10-1 C) 4 × 10-1 D) 4.166 × 10-1 E) 4.17 × 10 -1 Answer: E 24) What is 34 + (3) × (1.2465) written with the correct number of significant figures? A) 38
B) 37.74
C) 37.7395
D) 37.7
E) 4 × 101
24)
Answer: A 25) What is 56 + (32.00)/(1.2465 + 3.45) written with the correct number of significant figures? A) 62.81 B) 62.8123846 C) 62.812 D) 62.8 E) 63
25)
Answer: E 26) Add 3685 g and 66.8 kg and express your answer in milligrams (mg). A) 7.05 × 104 mg B) 7.05 × 107 mg C) 7.05 × 106 mg
D) 7.05 × 105 mg
26)
Answer: B 27) Express (4.3 × 106)-1/2 in scientific notation. A) 2.1 × 103 B) 4.8 × 10-4
C) 2.1 × 104
Answer: B 3
27) D) 2.1 × 10-5
28) What is 0.205 2/3, expressed to the proper number of significant figures? A) 0.3 B) 0.35 C) 0.3477
D) 0.348
28)
Answer: D 29) The length and width of a rectangle are 1.125 m and 0.606 m, respectively. Multiplying, your calculator gives the product as 0.68175. Rounding properly to the correct number of significant figures, the area should be written as A) 0.7 m2. B) 0.68 m2 . C) 0.682 m2 . D) 0.6818 m2 . E) 0.68175 m2 .
29)
Answer: C 30) The following exact conversion equivalents are given: 1 m = 100 cm , 1 in = 2.54 cm, and 1 ft = 12 in. If a computer screen has an area of 1.27 ft2 , this area is closest to
30)
A) 0.0465 m 2 . B) 0.00284 m 2 . C) 0.118 m 2 . D) 0.284 m 2 . E) 4.65 m 2 .
Answer: C 31) In addition to 1 m = 39.37 in., the following exact conversion equivalents are given: 1 mile = 5280 ft , 1 ft = 12 in , 1 hour = 60 min, and 1 min = 60 s. If a particle has a velocity of 8.4 miles per hour,its velocity, in m/s, is closest to A) 3.0 m/s. B) 3.8 m/s. C) 4.5 m/s. D) 4.1 m/s. E) 3.4 m/s.
31)
Answer: B 32) A weight lifter can bench press 171 kg. How many milligrams (mg) is this? A) 1.71 × 108 mg B) 1.71 × 109 mg C) 1.71 × 107 mg
D) 1.71 × 106 mg
32)
Answer: A 33) How many nanoseconds does it take for a computer to perform one calculation if it performs 6.7 × 107 calculations per second? A) 15 ns
B) 67 ns
C) 65 ns
33)
D) 11 ns
Answer: A 34) The shortest wavelength of visible light is approximately 400 nm. Express this wavelength in centimeters. A) 4 × 10-5 cm B) 4 × 10-11 cm C) 4 × 10-7 cm D) 400 × 10-11 cm E) 4 × 10-9 cm Answer: A
4
34)
35) The wavelength of a certain laser is 0.35 micrometers, where 1 micrometer = 1 × 10-6 m. Express this wavelength in nanometers. A) 3.5 × 103 nm B) 3.5 × 104 nm C) 3.5 × 101 nm D) 3.5 × 102 nm
35)
Answer: D 36) A certain CD-ROM disk can store approximately 6.0 × 102 megabytes of information, where 10 6 bytes = 1 megabyte. If an average word requires 9.0 bytes of storage, how many words can be stored on one disk? A) 6.7 × 107 words B) 2.0 × 109 words C) 2.1 × 107 words
36)
D) 5.4 × 109 words
Answer: A 37) A plot of land contains 5.8 acres. How many square meters does it contain? [1 acre = 43,560 ft 2 ] A) 5.0 × 104 m2 B) 2.3 × 104 m2 C) 7.1 × 103 m2 D) 7.0 × 104 m2
37)
Answer: B 38) A person on a diet loses 1.6 kg in a week. How many micrograms/second (µg/s) are lost? A) 2.6 × 103 µg/s B) 6.4 × 104 µg/s C) 1.6 × 105 µg/s D) 44 µg/s
38)
Answer: A SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 39) Albert uses as his unit of length (for walking to visit his neighbors or plowing his fields) the albert (A), the distance Albert can throw a small rock. One albert is 92 meters. How many square alberts is equal to one acre? (1 acre = 43,560 ft2 = 4050 m 2 )
39)
Answer: 1.29 A2 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 40) Convert a speed of 4.50 km/h to units of ft/min. (1.00 m = 3.28 ft) A) 246 ft/min B) 886 ft/min C) 82.3 ft/min D) 0.246 ft/min E) 165 ft/min
40)
Answer: A 41) The exhaust fan on a typical kitchen stove pulls 600 CFM (cubic feet per minute) through the filter. Given that 1.00 in. = 2.54 cm, how many cubic meters per second does this fan pull? A) 0.283 m3 /sec B) 3.05 m3 /sec C) 0.328 m3 /sec D) 32.8 m3 /sec
41)
Answer: A 42) The mass of a typical adult woman is closest to A) 35 kg. B) 150 kg.
C) 75 kg.
D) 20 kg.
42)
Answer: C 43) The height of the ceiling in a typical home, apartment, or dorm room is closest to A) 100 cm. B) 200 cm. C) 400 cm. D) 500 cm. Answer: B 5
43)
44) Approximately how many times does an average human heart beat in a year? A) 4 × 107 B) 4 × 109 C) 4 × 108 D) 4 × 105
E) 4 × 106
44)
Answer: A 45) Approximately how many times does an average human heart beat in a lifetime? A) 3 × 1010 B) 3 × 1011 C) 3 × 108 D) 3 × 109
E) 3 × 107
45)
Answer: D 46) Approximately how many pennies would you have to stack to reach an average 8-foot ceiling? A) 2 × 105 B) 2 × 103 C) 2 × 102 D) 2 × 104 E) 2 x 106
46)
Answer: B 47) Estimate the number of times the earth will rotate on its axis during a human's lifetime. A) 3 x 108 B) 3 × 104 C) 3 × 107 D) 3 × 105 E) 3 × 106
47)
Answer: B 48) Estimate the number of pennies that would fit in a box one foot long by one foot wide by one foot tall. A) 5 x 106 B) 5 × 102 C) 5 × 104 D) 5 × 103 E) 5 × 105
48)
Answer: C 49) A marathon is 26 mi and 385 yd long. Estimate how many strides would be required to run a marathon. Assume a reasonable value for the average number of feet/stride. A) 4.5 × 103 strides B) 4.5 × 104 strides C) 4.5 × 105 strides
49)
D) 4.5 × 106 strides
Answer: B 50) The period of a pendulum is the time it takes the pendulum to swing back and forth once. If the only dimensional quantities that the period depends on are the acceleration of gravity, g, and the length of the pendulum, , what combination of g and must the period be proportional to? (Acceleration has SI units of m · s -2 .). A) g/
B) g 2
C)
/g
D)
g
50)
E) g
Answer: C 51) The speed of a wave pulse on a string depends on the tension, F, in the string and the mass per unit length, µ, of the string. Tension has SI units of kg · m · s-2 and the mass per unit length has SI
51)
units of kg · m-1 . What combination of F and µ must the speed of the wave be proportional to?
A) F / µ
B)
µF
C) µ / F
D)
µ/F
E)
F/µ
Answer: A 52) The position x, in meters, of an object is given by the equation x = A + Bt + Ct2 , where t represents time in seconds. What are the SI units of A, B, and C? A) m/s, m/s2 , m/s3 B) m, s, s C) m, m, m
D) m, m/s, m/s2 E) m, s, s2 Answer: C 6
52)
Exam Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Consider a deer that runs from point A to point B. The distance the deer runs can be greater than the magnitude of its displacement, but the magnitude of the displacement can never be greater than the distance it runs. A) True B) False
1)
Answer: A 2) Which of the following quantities has units of a displacement? (There could be more than one correct choice.) A) 40 km southwest B) 186,000 mi C) 9.8 m/s2
2)
D) -120 m/s E) 32 ft/s2 vertically downward
Answer: A, B 3) Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object. A) The displacement is either greater than or equal to the distance traveled. B) The displacement is always equal to the distance traveled. C) The displacement can be either greater than, smaller than, or equal to the distance traveled. D) The displacement is either less than or equal to the distance traveled.
3)
Answer: D 4) Consider a car that travels between points A and B. The car's average speed can be greater than the magnitude of its average velocity, but the magnitude of its average velocity can never be greater than its average speed. A) True B) False
4)
Answer: A 5) Which of the following quantities has units of a velocity? (There could be more than one correct choice.) A) -120 m/s B) 186,000 mi C) 9.8 m/s2 downward
5)
D) 40 km southwest E) 9.8 m/s downward
Answer: A, E 6) When is the average velocity of an object equal to the instantaneous velocity? A) when the velocity is constant B) only when the velocity is increasing at a constant rate C) never D) always E) only when the velocity is decreasing at a constant rate Answer: A 1
6)
7) You drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. Your average speed over the 12 km drive will be A) greater than 70 km/h. B) less than 70 km/h. C) exactly 38 km/h. D) equal to 70 km/h. E) It cannot be determined from the information given because we must also know directions traveled.
7)
Answer: B 8) If the velocity of an object is zero at some point, then its acceleration must also be zero at that point. A) True B) False
8)
Answer: B 9) Which of the following situations is impossible? A) An object has velocity directed east and acceleration directed west. B) An object has constant non-zero velocity and changing acceleration. C) An object has velocity directed east and acceleration directed east. D) An object has zero velocity but non-zero acceleration. E) An object has constant non-zero acceleration and changing velocity.
9)
Answer: B 10) If the acceleration of an object is zero, then that object cannot be moving. A) True B) False
10)
Answer: B 11) If the velocity of an object is zero, then that object cannot be accelerating. A) True B) False
11)
Answer: B 12) Suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct? A) Since the car is slowing down, its acceleration must be negative. B) The acceleration is toward the west. C) The acceleration is zero. D) The acceleration is toward the east.
12)
Answer: D 13) An auto manufacturer advertises that their car can go "from zero to sixty in eight seconds." This is a description of what characteristic of the car's motion? A) average acceleration B) instantaneous speed C) instantaneous acceleration D) average speed E) displacement Answer: A
2
13)
14) An object moving in the +x direction experiences an acceleration of +2.0 m/s2 . This means the object A) is decreasing its velocity by 2.0 m/s every second. B) is traveling at 2.0 m/s. C) is increasing its velocity by 2.0 m/s every second. D) travels 2.0 m in every second.
14)
Answer: C 15) Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct? A) Its acceleration is zero. B) Its acceleration is in the -x direction. C) Its acceleration is in the +x direction. D) Its acceleration is decreasing in magnitude as the car slows down.
15)
Answer: B 16) Suppose that a car traveling to the west (-x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct? A) Its acceleration is zero. B) Its acceleration is negative. C) Its acceleration is decreasing in magnitude as the car slows down. D) Its acceleration is positive.
16)
Answer: D 17) Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct? A) The acceleration is a constant non-zero value. B) The acceleration is constantly increasing. C) The acceleration is constantly decreasing. D) The acceleration is equal to zero.
17)
Answer: D 18) If the velocity of an object is zero at one instant, what is true about the acceleration of that object? (There could be more than one correct choice.) A) The acceleration must be zero. B) The acceleration could be negative. C) The acceleration could be zero. D) The acceleration could be positive.
18)
Answer: B, C, D 19) Under what condition is average velocity equal to the average of the object's initial and final velocity? A) The acceleration is constant. B) The acceleration must be constantly increasing. C) This can occur only when the velocity is zero. D) This can only occur if there is no acceleration. E) The acceleration must be constantly decreasing. Answer: A
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19)
20) A racing car accelerates uniformly from rest along a straight track. This track has markers spaced at equal distances along it from the start, as shown in the figure. The car reaches a speed of 140 km/h as it passes marker 2.
20)
Where on the track was the car when it was traveling at half this speed, that is at 70 km/h? A) At marker 1 B) Between marker 1 and marker 2 C) Before marker 1
Answer: C 21) When a ball is thrown straight up with no air resistance, the acceleration at its highest point A) reverses from downward to upward B) is downward C) reverses from upward to downward D) is upward E) is zero
21)
Answer: B 22) A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct? A) The acceleration is downward at all points in the motion except that is zero at the highest point. B) On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero. C) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero. D) The acceleration is downward at all points in the motion. E) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration.
22)
Answer: D 23) Suppose a ball is thrown straight up and experiences no appreciable air resistance. What is its acceleration just before it reaches its highest point? A) exactly g B) slightly less than g C) slightly greater than g D) zero
23)
Answer: A 24) A ball is thrown straight up, reaches a maximum height, then falls to its initial height. Which of the following statements about the direction of the velocity and acceleration of the ball as it is going up is correct? A) Its velocity points upward and its acceleration points downward. B) Both its velocity and its acceleration point upward. C) Its velocity points downward and its acceleration points upward. D) Both its velocity and its acceleration points downward. Answer: A
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24)
25) A ball is thrown downward in the absence of air resistance. After it has been released, which statement(s) concerning its acceleration is correct? (There could be more than one correct choice.) A) Its acceleration is constant. B) Its acceleration is greater than g. C) Its acceleration is constantly decreasing. D) Its acceleration is zero. E) Its acceleration is constantly increasing.
25)
Answer: A 26) A 10-kg rock and a 20-kg rock are thrown upward with the same initial speed v 0 and experience
26)
no significant air resistance. If the 10-kg rock reaches a maximum height h, what maximum height will the 20-kg ball reach? A) h/2 B) h C) h/4 D) 4h E) 2h
Answer: B 27) A 10-kg rock and 20-kg rock are dropped from the same height and experience no significant air resistance. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground? A) 2T B) T/4 C) T D) 4T E) T/2
27)
Answer: C 28) A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a, what is the acceleration of the 20-kg rock? A) 4a B) 2a C) a/4 D) a/2 E) a
28)
Answer: E 29) Two objects are dropped from a bridge, an interval of 1.0 s apart. Air resistance is negligible. During the time that both objects continue to fall, their separation A) stays constant. B) increases at first, but then stays constant. C) decreases. D) decreases at first, but then stays constant. E) increases.
29)
Answer: E 30) From the edge of a roof top you toss a green ball upwards with initial speed v 0 and a blue ball
30)
downwards with the same initial speed. Air resistance is negligible. When they reach the ground below A) the two balls will have the same speed. B) the blue ball will be moving faster than the green ball. C) the green ball will be moving faster than the blue ball.
Answer: A 31) Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. Neglect air resistance. As time progresses, the difference in their speeds A) increases. B) decreases. C) remains constant. D) cannot be determined from the information given. Answer: C
5
31)
32) Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? Neglect air resistance. A) They are traveling at the same speed. B) The one thrown up is traveling faster. C) The one thrown down is traveling faster. D) It is impossible to tell because the height of the building is not given.
32)
Answer: A 33) Brick A is dropped from the top of a building. Brick B is thrown straight down from the same building, and neither one experiences appreciable air resistance. Which statement about their accelerations is correct? A) The acceleration of A is greater than the acceleration of B. B) Neither brick has any acceleration once it is released. C) The acceleration of B is greater than the acceleration of A. D) The two bricks have exactly the same acceleration.
33)
Answer: D 34) An object is moving with constant non-zero velocity in the +x direction. The position versus time graph of this object is A) a horizontal straight line. B) a vertical straight line. C) a straight line making an angle with the time axis. D) a parabolic curve.
34)
Answer: C 35) An object is moving with constant non-zero acceleration in the +x direction. The position versus time graph of this object is A) a horizontal straight line. B) a vertical straight line. C) a straight line making an angle with the time axis. D) a parabolic curve.
35)
Answer: D 36) An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is A) a horizontal straight line. B) a vertical straight line. C) a straight line making an angle with the time axis. D) a parabolic curve.
36)
Answer: A 37) An object is moving with constant non-zero acceleration in the +x direction. The velocity versus time graph of this object is A) a horizontal straight line. B) a vertical straight line. C) a straight line making an angle with the time axis. D) a parabolic curve. Answer: C
6
37)
38) The slope of a position versus time graph gives A) acceleration. C) the distance traveled.
B) velocity. D) displacement.
38)
Answer: B 39) The slope of a velocity versus time graph gives A) displacement. C) the distance traveled.
B) acceleration. D) velocity.
39)
Answer: B 40) If the position versus time graph of an object is a horizontal line, the object is A) moving with constant non-zero speed. B) moving with constant non-zero acceleration. C) at rest. D) moving with increasing speed.
40)
Answer: C 41) If the velocity versus time graph of an object is a horizontal line, the object is A) moving with zero acceleration. B) moving with constant non-zero acceleration. C) at rest. D) moving with increasing speed.
41)
Answer: A 42) If the velocity versus time graph of an object is a straight line making an angle of +30° (counter clockwise) with the time axis, the object is A) moving with constant non-zero speed. B) moving with constant non-zero acceleration. C) at rest. D) moving with increasing acceleration.
42)
Answer: B 43) The motions of a car and a truck along a straight road are represented by the velocity-time graphs in the figure. The two vehicles are initially alongside each other at time t = 0.
At time T, what is true of the distances traveled by the vehicles since time t = 0? A) The car will have travelled further than the truck. B) The truck will have travelled further than the car. C) The truck will not have moved. D) They will have traveled the same distance.
Answer: B
7
43)
44) Which of the following graphs represent an object at rest? (There could be more than one correct choice.)
A) graph a
B) graph b
C) graph c
Answer: A
8
D) graph d
E) graph e
44)
45) Which of the following graphs represent an object having zero acceleration?
45)
A) only graph a B) only graph b C) graphs b and c D) graphs a and b E) graphs c and d Answer: D 46) The figure shows a graph of the position x of two cars, C and D, as a function of time t.
According to this graph, which statements about these cars must be true? (There could be more than one correct choice.) A) At time t = 10 s, both cars have the same velocity. B) The cars meet at time t = 10 s. C) Both cars have the same acceleration. D) The magnitude of the acceleration of car C is less than the magnitude of the acceleration of car D. E) The magnitude of the acceleration of car C is greater than the magnitude of the acceleration of car D.
Answer: B, C
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46)
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 47) The graph in the figure shows the position of an object as a function of time. The letters H-L represent particular moments of time.
(a) At which moment in time is the speed of the object the greatest? (b) At which moment in time is the speed of the object equal to zero?
Answer: (a) J
(b) I
10
47)