                        EOC 2009 Part 1 (1-20)
Accessed 10 June 2017 at http://www.NCpublicschools.org
released Fall 2009

 A B C D
1. An object is launched across a room. How can a student determine the average horizontal velocity of the object using a meter stick and a calculator?
1. The student can calculate the object's initial potential energy and then calculate the velocity from conservation of energy principle.
2. The student can measure the recoil distance of the throwing mechanism and then calculate the velocity from conservation of momentum principle.
3. The student can measure the horizontal travel distance, compute the flight time from the vertical drop, and then calculate the average horizontal velocity.
4. The student can measure the fall distance and the travel time from the horizontal displacement and then calculate the average horizontal velocity.
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2. The graph shows the acceleration of a car over time. If the car starts from rest, what is the velocity of the car after 5.0 seconds?
1. 0 m/s
2. 0.80 m/s
3. 4.0 m/s
4. 20. m/s
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3. A car travels at a constant speed on a flat, circular track. Which factor, when doubled, will decrease the centripetal force on the car?
1. mass of the car
2. weight of the car
3. velocity of the car
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4. Neglecting air resistance, if a ball is thrown 4.5 m/s horizontally from a 94-m cliff, how far has the ball fallen after 2.7 s?
1. 36 m
2. 48 m
3. 58 m
4. 71 m
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5. Which graph represents the relationship between the gravitational acceleration of a falling body and the mass of the body?
1. 2. 3. 4. A B C D
6. These diagrams represent two examples of signs hanging from identical ropes. Which example would most likely be able to support the heaviest sign?
1. example I, because the ropes exert the greatest horizontal force on the sign
2. example II, because the ropes exert the greatest horizontal force on the sign
3. example I, because the ropes exert the greatest vertical force on the sign
4. example II, because the ropes exert the greatest vertical force on the sign
 A B C D
7. A horizontal force acts on a block sliding on a horizontal surface. The force of kinetic friction between the block and the surface is 0.5F. If the direction of the applied force is reversed, which is true?
1. The magnitude of the net force on the block increases.
2. The magnitude of the acceleration of the block remains the same.
3. The kinetic energy of the block increases.
4. The velocity of the block remains the same.
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8. A rope horizontally pulls a massive object lying on a surface with friction with a constant velocity. Wh describes the force on the rope?
1. equal to the frictional force
2. greater than the frictional force
3. equal to the weight of the object
4. greater than the weight of the object
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9. What is the difference in momentum between a 53-kg athlete running 3.58 m/s and a 880.-kg car traveling 1.03 m/s?
1. 130 kg • m/s
2. 720 kg • m/s
3. 1,100 kg • m/s
4. 2,100 kg • m/s
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10. A 13-N east horizontal force acts in the me direction as a 6.4-kg block as it slides 2.5 s on a frictionless, horizontal surface for 2.1 s. What is the speed of the block after force is applied?
1. 1.7 m/s
2. 4.3 m/s
3. 6.7 m/s
4. 7.2 m/s
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11. The chart represents the work output and the time to do the work for four machines. For which machine is the power output least?
1. I
2. II
3. III
4. IV
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12. A 290-N force is used to compress a spring. The spring constant of the spring is 5,880 N/m. How far is the spring compressed?
1. 0.0050 m
2. 0.049 m
3. 0.31 m
4. 20. m
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13. Figure 1 represents a pendulum. Figure 2 represents the motion of the pendulum as a wave. Points Z and W are the highest positions of the swinging mass. Point Y is halfway between points X and Z. Which graph represents the potential energy of the swinging mass at different points?
1. 2. 3. 4. A B C D
14. What is the maximum velocity at which a 25-W motor can lift a 8.5-kg object upward?
1. 0.3 m/s
2. 2.9 m/s
3. 7.6 m/s
4. 29 m/s
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15. What is the frequency of a wave with a speed of 10 m/s and wavelength of 20 m?
1. 0.5 Hz
2. 2 Hz
3. 30 Hz
4. 200 Hz
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16. The frequency of a wave is 5.1 × 1014 Hz. The speed of a wave in a certain medium is 2.1 × 108 m/s. What is the index of refraction of the medium?
1. 0.41
2. 0.73
3. 1.4
4. 2.4
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17. An object produces a sound with constant frequency as the object moves from X to Y. Which diagram represents the pattern of the sound?
1. 2. 3. 4. A B C D
18. The diagram represents a DC circuit. What is the voltage of the battery when the ammeter reads 4.0 amperes? What is the voltage of the battery when the ammeter reads 4.0 amperes?
1. 0.22 V
2. 1.0 V
3. 4.5 V
4. 16 V
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19. A student combs his hair with a plastic comb, and the hair becomes positively charged. What is the net charge of the comb and the hair and the direction of the charge transfer?
1. Protons move from the comb to the hair, and the total charge of the hair and the comb is zero.
2. Electrons move from the hair to the comb, and the total charge of the hair and the comb is zero.
3. Protons move from the comb to the hair, and the total charge of the hair and the comb is positive.
4. Electrons move from the hair to the comb, and the total charge of the hair and the comb is negative.
 A B C D
20. A student wants to measure the current flowing through and the voltage across R1 in the circuit. Which configuration is correct?
1. 2. 3. 4.  Additional North Carolina Exam Questions