Sample

Transcription

Sample
Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The figure below shows the position of a particle (moving along a straight line) as a function of
time. Which of the following statements is true?
1)
A) The object is accelerating (speeding up).
B) The object is moving at a constant velocity.
C) The object is deaccelerating (slowing down).
Answer: C
Explanation:
A)
B)
C)
2) An object has a velocity directed to the right, and an acceleration directed to the left. Which
statement is true?
A) The position of the object is not changing in time.
B) The position of the object is increasing to the right with time, and its speed is increasing.
C) The position of the object is increasing to the left with time, and its speed is increasing.
D) The position of the object is increasing to the right with time, and its speed is decreasing.
Answer: D
Explanation:
2)
A)
B)
C)
D)
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
3) A possible unit for the measure of time would be the period of your own pulse. Why might
this unit not be a good choice for a time standard?
Answer: In general, the human pulse rate often changes. Also, other people would in general,
have different pulse rates, so it would be difficult to reproduce the standard.
Explanation:
1
3)
4) If you needed to estimate the number of gallons of gasoline burned in the United States
each year by automobiles, what quantities would you need to assume? What formula
would you need to use?
4)
Answer: If you assumed
N = total number of cars
M = Average number of miles driven
each year per car
R = Average number of miles per gallon
Then
Total number of gallons =
N ·M
R
Explanation:
5) The length of a certain piece of wood is stated as 12.946 cm. Thinking in terms of accuracy
and significant figures, what value would you obtain if you measured this board with a
ruler whose smallest division is the millimeter?
5)
Answer: Since 1 cm = 10 mm, you could only measure this board to 1/10 of a centimeter,
therefore, 12.9 cm.
Explanation:
6) What are some advantages of using scientific notation to express very large or very small
numbers?
6)
Answer: The main advantage is the ability to express these numbers in a minimum amount
of space. For example,
1 trillion = 1,000,000,000,000
= 1 × 1012 .
Explanation:
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
7) The radius of a rotating turntable is 2.2 m. If it turns through an angle of 1.1 radians, through what
distance does a point on the edge move?
A) 2 m
B) 2.4 m
C) 0.5 m
D) 10 m
Answer: B
Explanation:
A)
B)
C)
D)
8) A record player turns through an angle of 4.50 radians. How many degrees does it turn through?
A) 198°
B) 258°
C) 129°
D) 108°
Answer: B
Explanation:
7)
A)
B)
C)
D)
2
8)
9) What is 0.2052/3, to the proper number of significant figures?
A) 0.3477
B) 0.348
C) 0.35
Answer: B
Explanation:
D) 0.3
A)
B)
C)
D)
10) Estimate the number of times an average person's heart beats in a lifetime. Assume the average
heart rate is 73 beats/min and a life span of 74 yr.
A) 3 × 108 beats
B) 3 × 1010 beats
C) 3 × 107 beats
D) 3 × 109 beats
Answer: D
Explanation:
D) 1.71 × 106 mg
13)
A)
B)
C)
D)
14) 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 × 104 strides
B) 4.5 × 103 strides
C) 4.5 × 106 strides
D) 4.5 × 105 strides
Answer: A
Explanation:
12)
A)
B)
C)
D)
13) A weight lifter can bench press 171 kg. How many milligrams (mg) is this?
A) 1.71 × 107 mg
B) 1.71 × 108 mg
C) 1.71 × 109 mg
Answer: B
Explanation:
11)
A)
B)
C)
D)
12) A plot of land contains 5.8 acres. How many square meters does it contain? [1 acre = 43,560 ft2 ].
A) 7.1 × 103 m2
B) 5.0 × 104 m2
C) 2.3 × 104 m2
D) 7.0 × 104 m2
Answer: C
Explanation:
10)
A)
B)
C)
D)
11) An oak tree was planted 22 years ago. How many seconds does this correspond to? (Do not take
leap days into account.)
A) 2.8 × 108
B) 6.9 × 108
C) 2.9 × 107
D) 1.2 × 107
Answer: B
Explanation:
9)
A)
B)
C)
D)
3
14)
15) A CD-ROM disk can store approximately 600.0 megabytes of information. If an average word
requires 9.0 bytes of storage, how many words can be stored on one disk?
A) 5.4 × 109 words
B) 2.0 × 109 words
C) 2.1 × 107 words
D) 6.7 × 107 words
Answer: D
Explanation:
A)
B)
C)
D)
16) A person on a diet loses 1.6 kg in a week. How many micrograms/second (µg/s) are lost?
A) 1.6 × 105 µg/s
B) 6.4 × 104 µg/s
C) 2.6 × 103 µg/s
D) 44 µg/s
Answer: C
Explanation:
16)
A)
B)
C)
D)
17) A car is travelling at 46.0 mi/hr. How many meters/second does the car cover?
A) 12.9 m/s
B) 20.6 m/s
C) 48.8 m/s
Answer: B
Explanation:
15)
D) 32.2 m/s
17)
A)
B)
C)
D)
18) An equation that you will use later is x =
1 2
at , where a has units of acceleration, t has units of time,
2
18)
and x has units of distance. If t = 61.9 s, find the difference between the values of x obtained when
a = 9.81 m/s2 and when a = 10.0 m/s2 .
A) 4 × 102 m
Answer: A
Explanation:
B) 1 × 103 m
C) 6 × 102 m
D) 3 × 102 m
A)
B)
C)
D)
19) Which of the following is a reasonable estimate of the number of characters (typed letters or
numbers) in a 858 page book? Assume an average of 163 words/page and a reasonable average
number of letters/word.
A) 6 × 105 char
B) 6 × 106
C) 6 × 104 char
D) 6 × 107 char
Answer: A
Explanation:
A)
B)
C)
D)
4
19)
20) The wavelength of a certain laser is 0.35 micrometers, where 1 micrometer = 1 × 10-6 m. What is
this wavelength in nanometers?
A) 3.5 × 101 nm
B) 3.5 × 102 nm
C) 3.5 × 104 nm
D) 3.5 × 103 nm
Answer: B
Explanation:
21) What is
A)
B)
C)
D)
0.674
to the proper number of significant figures?
0.74
A) 0.91
Answer: A
Explanation:
B) 0.9
C) 0.911
C) 4.8 × 10-4
D) 12.8 km/L
22)
D) 2.1 × 103
23)
A)
B)
C)
D)
24) Add 3685 g and 66.8 kg and express your answer in milligrams (mg).
A) 7.05 × 107 mg
B) 7.05 × 105 mg
C) 7.05 × 104 mg
Answer: A
Explanation:
D) 0.9108
A)
B)
C)
D)
23) Express [4.3 × 106 ]-1/2 in scientific notation.
A) 2.1 × 10-5
B) 2.1 × 104
Answer: C
Explanation:
21)
A)
B)
C)
D)
22) Your car gets 30.2 mi/gal on a trip. How many kilometers/liter did it get?
A) 28.2 km/L
B) 48.6 km/L
C) 7.97 km/L
Answer: D
Explanation:
20)
A)
B)
C)
D)
5
D) 7.05 × 106 mg
24)
25) How many nanoseconds does it take for a computer to perform one calculation if it performs
calculations
6.7 × 107
?
second
A) 67 ns
Answer: C
Explanation:
B) 65 ns
C) 15 ns
25)
D) 11 ns
A)
B)
C)
D)
TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false.
26) If a vector pointing to the right has a positive magnitude, then one pointing to the left has a
negative magnitude.
Answer:
True
Explanation:
False
27) If successive images of an object in a motion diagram get closer and closer together, then that object
is accelerating.
Answer:
True
Explanation:
32)
False
33) If an object has a changing speed, its velocity must also be changing; but if it has a changing
velocity, its speed is not necessarily changing.
Answer:
True
Explanation:
31)
False
32) All objects moving in a circle are accelerated.
Answer:
True
Explanation:
30)
False
31) Since vectors always have positive magnitudes, the sum of two vectors must have a magnitude
greater than the magnitude of either one of them.
Answer:
True
Explanation:
29)
False
30) If the average speed of an object is zero, then its average velocity must be zero; but if its average
velocity is zero, its average speed is not necessarily zero.
Answer:
True
Explanation:
28)
False
29) The change in the position vector of a moving object is equal to the distance it has moved.
Answer:
True
Explanation:
27)
False
28) If the final position vector of a moving object has a smaller magnitude than the initial position
vector, then the change in the object's position vector has a positive magnitude.
Answer:
True
Explanation:
26)
False
6
33)
34) If an object is accelerating toward a point, then it must be getting closer and closer to that point.
Answer:
True
Explanation:
False
7
34)
Answer Key
Testname: C1
1) C
2) D
3) In general, the human pulse rate often changes. Also, other people would in general, have different pulse rates, so it
would be difficult to reproduce the standard.
4) If you assumed
N = total number of cars
M = Average number of miles driven
each year per car
R = Average number of miles per gallon
Then
Total number of gallons =
N ·M
R
5) Since 1 cm = 10 mm, you could only measure this board to 1/10 of a centimeter, therefore, 12.9 cm.
6) The main advantage is the ability to express these numbers in a minimum amount of space. For example,
1 trillion = 1,000,000,000,000
= 1 × 1012 .
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
B
B
B
D
B
C
B
A
D
C
B
A
A
B
A
D
C
A
C
FALSE
TRUE
TRUE
FALSE
TRUE
FALSE
TRUE
TRUE
FALSE
8