EXAM 1 A
PHYS 102
SUMMER 2003
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The exam is closed book and closed notes.
Make sure you put your name on the SCANTRON form.
Here are some useful equations:
Vectors: Ax = A cos;
R=A+B
A = Ax  Ay
2
Ay = A sin;
Rx = Ax+ Bx ,
v2  v0
x
2a
v  v2
x 1
t
2
Free-fall: y = vo t -
1 2
gt
2
v = vo - gt,
Projectile motion: x = voxt
v y 2  voy2
y
 2g
Fnet = ma,
y = v0yt xmax = R =
Fg = mg ,
 = tan-1
;
Ay
Ax
;
R y = A y + By
1
x = vot + at2
2
One-dimensional motion:
2
y
1 2
gt
2
vo 2 sin 2
;
g
v2  vo
 2g
2
v = vo + at
2
2ax = v2 - v02
2
y max 
v0
2g
vy = voy - gt
xmax = voxttot
t tot 
vox = vocos
2 vo
g
voy = vosin
EXAM 1A PHYS 102 SUMMER 2003 NAME_______________________________________SCORE_________
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1. A vector A in the x,y plane has an x component of 24 and an y component of 24. The direction (angle the vector A
makes with the positive x axis) of this vector is closest to:
A) 26°
B) 30°
C) 45°
D) 127°
E) 210°
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2. A woman walks 180 m in the direction 650 north of east, then 80 m directly east. Find the
magnitude of the displacement vector A + B.
B
A) 100 m
A
B) 146 m
C) 226 m
D) 440 m
650
E) 558 m
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3. A particle moves along a straight path with a velocity v that varies with time t as
shown in the graph. How far from its initial position at t = 0 will the particle be when t
= 6 seconds?
A) 6 m
B) 12 m
C) 18 m
D) 36 m
E) 44 m
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4. A car moving initially at 12 m/s, travels 180 m in 6 s along a straight line with
constant acceleration. The acceleration of the car is:
A) 0. 0 m/s2
B) 0..5 m/s2
C) 1..5 m/s2
D) 3. 0 m/s2
E) 6. 0 m/s2
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5. If a car traveling at 60 km/h suddenly locks its brakes and skids 80 m, how long will it take for the car to come to a
complete stop?
A) 1.2 s
B) 2.4 s
C) 4.8 s
D) 9.6 s
E) 15.4 s
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6. A stone is thrown vertically upward with an initial speed of 16 m/s. Its position 2 seconds later is:
A) 12.4 m
B) 26.2 m
C) 32.4 m
D) 38.5 m
E) 46.0 m
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7. A 60 kg ball is dropped from a height of 48 m above a table. What is the velocity of the ball just before impact?
A) 11 m/s
B) 15 m/s
C) 22 m/s
D) 31 m/s
E) 45 m/s
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A projectile is fired over level ground with an initial velocity 50 m/s at an angle 350 above the horizontal.
8. The horizontal and vertical components of its velocity 4 seconds later are closest to:
A) vx = 41 m/s, vy = 9 m/s
B) vx = 25 m/s, vy = 18 m/s
C) vx = 41 m/s, vy = -10.5 m/s
D) vx = 25 m/s, vy = -8 m/s
E) vx = 41 m/s, vy = 21 m/s
9. What is the maximum height reached by the projectile?
A) 6 m
B) 12 m
C) 18 m
D) 36 m
E) 44 m
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10. A ball thrown horizontally from a point 8 m above the ground, strikes the
ground after traveling horizontally a distance of 18 m With what speed was it
thrown?
A) 2.0 m/s
B) 7.0 m/s
C) 8.0 m/s
D) 11.0 m/s
E) 14.0 m/s
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11. In the absence of all forces, a moving object will
A) slow down and eventually stop.
B) move at constant velocity.
C) immediately come to rest.
D) accelerate.
E) none of the above.
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12. Starting from rest, a 8-kg body reaches a speed of 6 m/s in a distance of 4 m. What is the net force acting on the body?
A) 16 N
B) 28 N
C) 36 N
D) 65 N
E) 98 N
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13. An object of mass M is suspended by a string form the ceiling inside an elevator. The elevator is traveling upward with
a constant speed. The tension in the string is
A) equal to Mg.
B) less then Mg.
C) greater then Mg.
D) impossible to tell without knowing the speed.
E) none of the above.
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14. A 6-kg suitcase is placed on a scale that is in an elevator moving with upward
acceleration of 2.0 m/s2. What does the scale read?
A) 57 N
B) 71 N
C) 86 N
D) 91 N
E) none of the above
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A 38-kg crate is pulled along a horizontal, frictionless floor
by a cord that exerts a 180-N tension force at an angle  = 300 as shown .
T
15. The acceleration of the block is closest to
A) 1.8 m/s2
B) 2. 4 m/s2
C) 3.6 m/s2
D) 4.1 m/s2
E) 8.5 m/s2

M
16. The normal force on the block is closest to
A) 110 N
B) 146 N
C) 185 N
D) 211 N
E) 282 N
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17. An object of mass M is suspended by a string form the ceiling inside an elevator. The elevator is traveling upward with
a constant speed. The tension in the string is
A) equal to Mg.
B) less then Mg.
C) greater then Mg.
D) impossible to tell without knowing the speed.
E) none of the above.
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18. Block B, which has a mass of 100 kg, is raised from the Earth's surface by means of
pulley system shown. If the tension F in the string has a magnitude of 1200 N, what is the
acceleration of the block B ?
A) 12 m/s2
B) 8 m/s2
C) 6 m/s2
D) 4 m/s2
E) 2 m/s2
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