                        EOC 2009 Part 3 (41-62)
Accessed 10 June 2017 at http://www.NCpublicschools.org
released Fall 2009

 A B C D
41. Two charged particles are 0.080 m apart. They are moved until the force between them is 16 times greater. How far apart are the charges?
1. 0.0050 m
2. 0.020 m
3. 0.040 m
4. 0.16 m
 A B C D
43. The graph represents the motion of a car moving linearly. When is the car moving backwards?
1. 0 s to 10 s
2. 20 s to 40 s
3. 40 s to 50 s
4. 50 s to 60 s
 A B C D
44. The average speed of a cart during a 15-s interval is 3.0 m/s. What is the total distance traveled by the cart?
1. 0.20 m
2. 5.0 m
3. 18 m
4. 45 m
 A B C D
45. A car travels at 11 m/s east for 61 s, then travels at 25 m/s east for 31 s. What is the average velocity of the car?
1. 8.5 m/s east
2. 16 m/s east
3. 18 m/s east
4. 36 m/s east
 A B C D
46. An object moves in uniform circular motion, and the centripetal force on the object is 4.0 N. If the mass of the object decreases by a factor of 2, what will be the centripetal force on the object?
1. 1.0 N
2. 2.0 N
3. 8.0 N
4. 16 N
 A B C D
47. The objects shown are moving in a horizontal, uniform, circular motion. Which object experiences the least centripetal force?
1. 2. 3. 4. A B C D
48. A 730-N person pulls a rope tied to a tree. If the person pulls the rope with a force of 120 N, what is the magnitude of the reaction force on the rope?
1. 120 N
2. 610 N
3. 730 N
4. 850 N
 A B C D
49. The diagram represents forces acting on a block that accelerates 6.0 m/s/s on a frictionless surface. What is the mass of the block?
1. 2.0 kg
2. 4.0 kg
3. 12 kg
4. 72 kg
 A B C D
50. A 2.6-kg block rests on a plane inclined at 35° to the horizontal. What is the frictional force acting on the block?
1. 11 N
2. 15 N
3. 22 N
4. 26 N
 A B C D
51. A 2-kg body of mass is moving on a horizontal frictionless surface with a velocity of 4 m/s. What is the net force required to keep the body moving with the same velocity and direction for 5 s?
1. 0 N
2. 2 N
3. 8 N
4. 20 N
 A B C D
52. An object has a mass, m, and velocity, v. Which change would make its momentum become one-fourth as much?
1. Its mass becomes ½m, and velocity becomes ½v.
2. Its mass remains m, and its velocity becomes ½v.
3. Its mass becomes 2m, and its velocity becomes ¼v.
4. Its mass becomes ½m, and velocity becomes 2v.
 A B C D
53. A 75-kg object traveling 15 m/s collides with and sticks to a 315-kg object initially at rest. What is the final velocity of the two objects?
1. 2.9 m/s
2. 3.6 m/s
3. 12 m/s
4. 19 m/s
 A B C D
54. How much power is required to lift a 12-N box at 4.5 m/s?
1. 2.6 W
2. 5.4 W
3. 44 W
4. 54 W
 A B C D
55. A student drops a 0.45-kg ball that hits the floor with a speed of 5.3 m/s. If the velocity of the ball is 4.8 m/s when it hits the floor on the second bounce, how much mechanical energy is lost during the first bounce?
1. 0 J
2. 1.1 J
3. 4.8 J
4. 6.3 J
 A B C D
56. A pendulum swings back and forth up to a maximum height of 1.52 m. Neglecting friction, what is the speed of the pendulum at the lowest position?
1. 2.7 m/s
2. 3.9 m/s
3. 5.5 m/
4. 30. m/s
 A B C D
57. The diagram represents two pulses traveling toward each other. Which represents what happens when the pulses meet?
1. 2. 3. 4. A B C D
58. This graph represents a wave created by a student who hits a 220-Hz tuning fork with a certain force. The student hits a 440-Hz tuning fork with the same force. Which graph represents the new wave?
1. 2. 3. 4. A B C D
59. A student places a piece of glass over a tank of water. What happens to the speed of a light ray that shines from air through glass into the water?
1. increases in glass and water
2. decreases in glass and water
3. increases in glass, then decreases in water
4. decreases in glass, then increases in water
 A B C D
60. In these diagrams, all light bulbs are identical. In which circuit would the light bulbs be the dimmest?
1. 2. 3. 4. A B C D
61. What happens when a positively charged rod touches a neutral metal sphere?
1. Protons move from the sphere to the rod.
2. Protons move from the rod to the sphere.
3. Electrons move from the sphere to the rod.
4. Electrons move from the rod to the sphere.
 A B C D
62. This diagram represents a DC circuit. Each resistor has a value of 5.1 Ω. If R3 is removed from the circuit, how much current will flow through the circuit?
1. 1.2 A
2. 1.6 A
3. 2.4 A
4. 4.8 A Additional North Carolina Exam Questions