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6. The correct answer is (C). Definition.
7. The correct answer is (A). Definition.
8. The correct answer is (E). When an object undergoing harmonic motion has a displacement of zero,
it is at the equilibrium position. The restoring force will therefore be zero. If the force is zero, then
the acceleration must necessarily be zero as well. Recall the relationship:
F = ma
if F = 0,
then ma = 0 and
∴ a=0
9. The correct answer is (C). The distance value is unchanged.
1.
E
2.
B
3.
D
4.
B
5.
C
6.
C
7.
A
8.
E
9.
C
10.
A
11.
D
12.
B
13.
A
14.
C
15.
B
16.
B
17.
E
18.
D
19.
C
20.
E
21.
B
22.
D
23.
D
24.
A
25.
B
26.
B
27.
C
28.
B
29.
C
30.
C
31.
D
32.
D
33.
E
34.
D
35.
C
36.
D
37.
E
38.
B
39.
E
40.
E
41.
A
42.
C
43.
B
44.
E
67.
D
68.
C
69.
A
70.
A
71.
B
72.
C
73.
B
74.
D
75.
D
45.
A
46.
D
47.
D
48.
A
49.
C
50.
A
51.
C
52.
E
53.
A
54.
B
55.
C
56.
E
57.
B
58.
B
59.
C
60.
D
61.
B
62.
B
63.
C
64.
C
65.
D
66.
A

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Lesson 11
320
w w w . p e t e r s o n s . c o m / a r c o
ARCO
■ SAT II Subject Tests
10. The correct answer is (A). Velocity is defined as the change in displacement (distance in this case)
per unit time:
v
d
t
= ∆
∆
Hence, (A) has the greatest constant velocity as it has the greatest change in distance per unit time.
Note that constant velocity is represented by a straight line in this diagram.
11. The correct answer is (D). Acceleration is defined as the change in velocity per unit time:
a
v
t
= ∆
∆
As lines A, B, and C are straight, each represents a constant velocity. Therefore, as acceleration is the
change in velocity per unit time, the acceleration of A, B, and C is zero. The curvilinear representa-
tions—D and E—demonstrate positive and negative accelerations, respectively. Object D has the
greatest acceleration as it possesses the greatest change in velocity per unit time.
12. The correct answer is (B). Definition. The number of protons plus the number of neutrons within a
given nucleus represents the mass number of the element.
13. The correct answer is (A). The atomic number is the defining characteristic of an atom.