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; Ay = A sin; A =; = tan-1;
R = A + B Rx = Ax+ Bx , Ry = Ay + By
One-dimensional motion: x = vot +at2 v = vo + at 2ax = v2 - v02
Free-fall: y = vo t - gt2 v = vo - gt,
Projectile motion: x = voxt y = v0yt - gt2 vy = voy - gt vox = vocos voy = vosin xmax = R = xmax = voxttot
Fnet = ma, Fg = mg , Incline: Fgx = mgsin, Fgy = mgcos
SAMPLE EXAM 1 PHYS 102 SUMMER SESSION
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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.
A) 100 m
B) 146 m
C) 226 m
D) 440 m
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) 42 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. 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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13. 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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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 .
14. 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
15. 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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16. 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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17. A 10-kg block on a frictionless, horizontal plane is pulled by a cord over a massless, frictionless pulley . What tension force T is needed so that the 10-kg block can move at acceleration of 2.8 m/s2 ?
A) 12 N
B) 28 N
C) 42 N
D) 65 N
E) 98 N
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18. A 5-kg box sitting on a horizontal surface is pulled by a 15-N force. A 5-N friction force retards the motion. The acceleration of the object is closest to
A) 2.0 m/s2
B) 3.0 m/s2
C) 4.0 m/s2
D) 5.0 m/s2
E) 6.0 m/s2
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A 2-kg block, initially at rest, slides down a frictionless inclined plane. Angle of incline is
350, and incline is 0.8 m long.
19. The normal force on the block is closest to
A) 11 N
B) 16 N
C) 25 N
D) 31 N
E) 43 N
20. Find the speed of the block at the bottom of the incline.
A) 1.80 m/s
B) 3.00 m/s
C) 5.60 m/s
D) 7.20 m/s
E) 8.50 m/s
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