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2014 AP 2 Finals Review MC- answers are starred
1. Which one of the following statements concerning vectors and scalars is false?
A) In calculations, the vector components of a vector may be used in place of the vector itself.
B) It is possible to use vector components that are not perpendicular.
C) A scalar component may be either positive or negative.
*D) A vector that is zero may have components other than zero.
E) Two vectors are equal only if they have the same magnitude and direction.
2.. Use the component method of vector addition to find the resultant of the following three
vectors:
A = 56 km, east
B = 11 km, 22° south of east
C = 88 km, 44° west of south
A) 81 km, 14° west of south
B) 97 km, 62° south of east
C) 52 km, 66° south of east
*D) 68 km, 86° south of east
E) 66 km, 7.1° west of south
3. Two vectors, A and B , are added together to form the vector C = A + B .
The relationship between the magnitudes of these vectors is given by:
Cx = 0
Cy = A sin 60° + B sin 30°
Ax and Ay point in the positive x and y directions, respectively.
Which one of the following statements best describes the orientation of vectors A and B ?
A) A and B point in opposite directions.
*B) A points 60° above the positive x axis while B points 30° above the negative x axis.
C) A points 60° above the negative x axis while B points 30° above the positive x axis.
D) A points 60° below the positive x axis while B points 30° above the positive y axis.
E) A points 60° below the positive x axis while B points 30° below the positive y axis.
4. Ryan throws a tennis ball vertically upward. The ball returns to the point of release after 3.5
s. What is the speed of the ball as it is released?
A) 0 m/s
B) 14 m/s
*C) 17 m/s
D) 21 m/s
E) 34 m/s
5. Starting from rest, a particle that is confined to move along a straight line is accelerated at a
rate of 5.0 m/s2. Which statement concerning the slope of the position versus time graph for this
particle is true?
A) The slope has a constant value of 5.0 m/s.
B) The slope has a constant value of 5.0 m/s2.
C) The slope is both constant and negative.
*D) The slope is not constant and increases with increasing time.
E) The slope is not constant and decreases with increasing time.
6. A automotive test driver travels due north in a prototype hybrid vehicle at 30 mi/h for 2 hours.
She then reverses her direction and travels due south at 60 mi/h for 1 hour.
What is the average velocity of the vehicle?
*A) zero mi/h
B) 40 mi/h, north
C) 40 mi/h, south
D) 45 mi/h, north
E) 45 mi/h, south
7. A shell is fired with a horizontal velocity in the positive x direction from the top of an 80-m
high cliff. The shell strikes the ground 1330 m from the base of the cliff. The drawing is not to
scale.
Determine the initial speed of the shell.
A) 4.0 m/s
B) 9.8 m/s
C) 82 m/s
D) 170 m/s
*E) 330 m/s
8. What is the magnitude of the velocity of the shell as it hits the ground?
A) 4.0 m/s
B) 9.8 m/s
C) 82 m/s
D) 170 m/s
*E) 330 m/s
9. A basketball player is running at a constant speed of 2.5 m/s when he tosses a basketball
upward with a speed of 6.0 m/s. How far does the player run before he catches the ball? Ignore
air resistance.
*A) 3.1 m
B) 4.5 m
C) The ball cannot be caught because it will fall behind the player.
D) 6.0 m
E) 7.5 m
10. A crate rests on the flatbed of a truck that is initially traveling at 15 m/s on a level road. The
driver applies the brakes and the truck is brought to a halt in a distance of 38 m. If the
deceleration of the truck is constant, what is the minimum coefficient of friction between the
crate and the truck that is required to keep the crate from sliding?
A) 0.20
*B) 0.30
C) 0.39
D) 0.59
E) This cannot be determined without knowing the mass of the crat
11. A rock is suspended from a string; and it accelerates downward. Which one of the following
statements concerning the tension in the string is true?
A) The tension points downward.
*B) The tension is less than the weight of the rock.
C) The tension is equal to the weight of the rock.
D) The tension is greater than the weight of the rock.
E) The tension is independent of the magnitude of the rock's acceleration
12. A muscle builder holds the ends of a massless rope. At the center of the rope, a 7.9-kg ball
is hung as shown.
What is the tension in the rope if the angle  in the drawing is 6.0°?
A) 960 N
B) 740 N
*C) 370 N
D) 230 N
E) 150 N
13. A 10-kg block is pushed against a vertical wall by a horizontal force of 100 N as shown in
the figure. The coefficient of static friction, s, between the block and the wall is 0.60; and the
coefficient of kinetic friction, k, is 0.40. Which one of the following statements is true, if the
block is initially at rest?
A) The total force exerted on the block by the wall is directed horizontally.
B) The block slides down the wall with an acceleration of magnitude 3.8 m/s2.
*C) The block will slide down the wall because the force of static friction can be no larger than
60 N.
D) The block will remain at rest because the coefficient of static friction is greater than the
coefficient of kinetic friction.
E) The block will slide down the wall because the coefficient of kinetic friction is less than the
coefficient of static friction
14. A 20.0-kg package is dropped from a high tower in still air and is "tracked" by a radar
system. When the package is 25 m above the ground, the radar tracking indicates that its
acceleration is 7.0 m/s2. Determine the force of air resistance on the package.
*A) 56 N
B) 28 N
C) 280 N
D) 196 N
E) 140 N
15. A man stands on a spring scale in a moving elevator and notices that the scale reading is
20% larger than when he weighs himself in his bathroom. Which statement can not be true?
A) The tension in the supporting cable must exceed the weight of the elevator and its contents.
B) The speed of the elevator changes by equal amounts in equal times.
C) The elevator could be moving upward with increasing speed.
D) The elevator could be moving downward with decreasing speed.
*E) The elevator could be moving upward at constant speed.
16. An artificial satellite in a circular orbit around the Sun has a period of 8 years. Determine
the ratio of the satellite's orbital radius to that of the earth's orbital radius. Assume that the earth's
orbit around the Sun is circular.
A) 1
B) 2
*C) 4
D) 8
E) 23
17. What is the acceleration due to gravity at an altitude of 1.00 × 106 m above the earth's
surface? Note: the radius of the earth is 6.38 × 106 m.
A) 3.99 m/s2
B) 9.80 m/s2
C) 5.00 m/s2
D) 6.77 m/s2
*E) 7.32 m/s2
18. A 0.75-kg ball is attached to a 1.0-m rope and whirled in a vertical circle. The rope will
break when the tension exceeds 450 N. What is the maximum speed the ball can have at the
bottom of the circle without breaking the rope?
*A) 24 m/s
B) 12 m/s
C) 32 m/s
D) 16 m/s
E) 38 m/s
19. Two boxes are connected to each other as shown. The system is released from rest and the
1.00-kg box falls through a distance of 1.00 m. The surface of the table is frictionless. What is
the kinetic energy of box B just before it reaches the floor?
*A) 2.45 J
B) 4.90 J
C) 9.80 J
D) 29.4 J
E) 39.2 J
20. The initial velocity of a 4.0-kg box is 11 m/s, due west. After the box slides 4.0 m
horizontally, its speed is 1.5 m/s. Determine the magnitude and the direction of the nonconservative force acting on the box as it slides.
A) 42 N, due west
B) 120 N, due east
C) 31 N, due east
*D) 59 N, due east
E) 83 N, due west
21. An escalator is 30.0 meters long and slants at 30.0° relative to the horizontal. If it moves at
1.00 m/s, at what rate does it do work in lifting a 50.0-kg woman from the bottom to the top of
the escalator?
A) 49.3 W
B) 98.0 W
*C) 245 W
D) 292 W
E) 495 W
22. While a car is stopped at a traffic light in a storm, raindrops strike the roof of the car. The
area of the roof is 5.0 m2. Each raindrop has a mass of 3.7 × 10–4 kg and speed of 2.5 m/s before
impact and is at rest after the impact. If, on average at a given time, 150 raindrops strike each
square meter, what is the impulse of the rain striking the car?
*A) 0.69 N  s
B) 0.046 N  s
C) 0.14 N  s
D) 11 N  s
E) 21 N  s
23. A cable stretches by an amount d when it supports a crate of mass M. The cable is then cut
into three equal pieces. If the same crate is supported by any one of these pieces, by how much
will the cable stretch?
A) d
*B) d/3
C) d/6
D) 3d
E) 9d
24. Within a certain type of star called a neutron star, the material at the center has a mass
density of 1.0 × 1018 kg/m3. If a tiny sphere of this material of radius 1.0 × 10–5 m were
somehow transported to the surface of the earth, what would be the weight of this sphere?
A) 1000 N
B) 4200 N
*C) 4.1 × 104 N
D) 7.0 × 104 N
E) 3.8 × 109 N