HOMEWORK 2 – 17 Questions
Vectors
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1. Which of the following is a scalar quantity?
a) velocity
b) acceleration
c) displacement
d) mass
e) force
2. Which of the following statements is a true statement?
a) A vector can have positive or negative magnitudes.
b) A vector's magnitude cannot be more than the magnitude of one of its
components.
c) A vector's magnitude cannot be less than the sum of the magnitude of its
components.
d) If the x-component of a vector is smaller than its y-component then that vector is
in the opposite direction to its y-component.
e) The magnitude of a vector cannot be zero unless all of its components are zero.
3. Refer to the following figure:
The components of vectors A and B are
a) a) Ax = 0
Bx = B sin 30°
b) b) Ax = A sin90°
Bx = B cos60°
c) c) Ax = A cos0°
Bx = -B cos60°
d) d) Ax = A cos90°
Bx = B sin60°
e) e) Ax = A cos90°
Bx = 0
Ay = 0
Ay = A cos90°
Ay = A cos90°
Ay = A sin90°
Ay = A sin90°
By = B cos30°
By = B sin60°
By = B cos30°
By = B cos60°
By = 0
4. Refer to the figure below. Vector S as expressed in terms of vectors M and N is given
by
a) M + N
b) M – N
c) M
d) N
e) None of the other choices is correct.
5. Refer to the figure below. Three forces F1 = F2 = F3 = 70 N are acting on an object O
as shown in the figure. Which one of the following statements is true regarding the
resultant force acting over the object O?
a)
b)
c)
d)
e)
The resultant force is 35 N
The resultant force is 70 N
The resultant force is 140 N
The resultant force is 210 N
The resultant force is zero
6. A car travels along east and its velocity decreases. The acceleration of the car is in
which of the following directions?
a) Eastward
b) Westward
c) Northward
d) Southward
e) Cannot be determined without additional information.
7. A soccer player carries the ball for a distance of 40.0 m in the direction 42.0° west of
south. Find the westward component of the ball's displacement.
a) 26.8 m
b) 29.7 m
c) 32.2 m
d) 36.0 m
e) None of the other choices is correct.
8. A vector A has components Ax = 12 m and Ay = 5.0 m. What is the magnitude of
vector A?
a) 7.0 m
b) 13 m
c) 17 m
d) 60 m
e) 169 m
9. A boy jumps at a speed of 20.0 m/s at an angle of 25.0° above the horizontal. What is
the horizontal component of the boy's velocity?
a) 18.1 m/s
b) 15.6 m/s
c) 8.45 m/s
d) 12.6 m/s
e) 9.33 m/s
10. Vector M = 4.00 m points eastward and vector N = 3.00 m points northward. The
resultant vector M + N is given by
a) 5.00 m at an angle 71.6° north of east.
b) 5.00 m at an angle 36.9° north of east.
c) 5.00 m at an angle 53.1° north of east.
d) 5.00 m at an angle 18.4° north of east.
e) 5.00 m at an angle 26.6° north of east.
11. The components of vectors M and N are as follows: M (1, -1) and N (2, 4). The
components of the resultant vector M - N are given by
a) (-1, -5)
b) (3, 3)
c) (1, -5)
d) (0, 4)
e) (-1,3)
12. Vector A = 6.0 m and points 30° south of east. Vector B = 4.0 m and points 30° west
of south. The resultant vector A + B is given by
a) 7.2 m at an angle 64° south of east.
b) 3.3 m at an angle 64° south of east.
c) 9.8 m at an angle 26° south of east.
d) 9.8 m at an angle 64° south of east.
e) 3.3 m at an angle 26° south of east.
13. Referring to the figure below:
choice
1
2
3
4
5
x-component
3.73 cm
-3.73 cm
-2.27 cm
2.27 cm
3.73 cm
y-component
2.20 cm
2.20 cm
0 cm
0 cm
-2.20 cm
The components of the vector sum are given by
a) Choice 1
b) Choice 2
c) Choice 3
d) Choice 4
e) Choice 5
14. A car moves from the point (3.0 m) x + (5.0 m) y to the point (8.0 m) x - (7.0 m) y
in 2.0 s. What is the magnitude of the average velocity of the car?
a) 6.5 m/s
b) 13 m/s
c) 9.0 m/s
d) 4.5 m/s
e) 3.3 m/s
15. A plane is headed eastward at a speed of 156 m/s. A 20.0 m/s wind is blowing
southward at the same time as the plane is flying. The velocity of the plane relative to the
ground is
a) 157 m/s at an angle 7.31° south of east.
b) 157 m/s at an angle 7.31° east of south.
c) 155 m/s at an angle 7.36° south of east.
d) 155 m/s at an angle 7.36° east of south.
e) 157 m/s at an angle 7.36° south of east.
16. A plane has an airspeed of 142 m/s. A 16.0 m/s wind is blowing southward at the
same time as the plane is flying. If the velocity of the plane relative to Earth is due east,
what is the magnitude of that velocity?
a) 16.2 m/s
b) 16.0 m/s
c) 158 m/s
d) 141 m/s
e) 48 m/s
17. Refer to the figure below. The magnitudes of the vectors shown in the figure are A =
7.0 cm, B = 6.0 cm, and C = 4.0 cm. The components of the resultant vector are given
by
Choice
1
2
3
4
5
a)
b)
c)
d)
e)
Choice 1
Choice 2
Choice 3
Choice 4
Choice 5
x-component
cm
-8.7
-11.3
0
-4.5
2.4
y-component
cm
-4.5
-4.5
2.4
-11.3
-8.7