                        NCFE 2019 Part1
Accessed 8 Sept 2019 at http://www.NCpublicschools.org

 A B C D
1. A small object attached to the end of a string is swung in a horizontal circle at a constant linear speed. The linear speed of the object is doubled, and the length of the string remains the same. What effect does the change have on the centripetal acceleration of the object?
1. It is reduced by half.
2. It remains the same.
3. It doubles.
 A B C D
2. Two rocks, one weighing 100 N and the other weighing 200 N, are dropped from a 50-m cliff at the same time. When both rocks are 10 m from the ground and air friction is ignored, which is the same?
1. acceleration
2. kinetic energy
3. momentum
4. potential energy
 A B C D
3. A ball is launched at an angle of 54° to the horizontal. What determines the amount of time the ball remains in flight? (Ignore air resistance.)
1. initial velocity
2. mass of the projectile
3. centripetal acceleration
4. composition of the projectile
 A B C D
4.Which statement correctly describes the motion of the object? 1. The object traveled 360 m during the 12 s and had a constant acceleration of 0 m/s/s.
2. The object traveled 360 m during the 12 s and had a constant acceleration of 5 m/s/s.
3. The object traveled 720 m during the 12 s and had a constant acceleration of 0 m/s/s.
4. The object traveled 720 m during the 12 s and had a constant acceleration of 5 m/s/s.
 A B C D
5. A 25-kg bucket is being lifted by a rope. The rope will break if it experiences more than 350 N of tension. What is the maximum upward acceleration the bucket can experience without breaking the rope?
1. 0.25 m/s/s
2. 0.40 m/s/s
3. 2.5 m/s/s
4. 4.2 m/s/s
 A B C D
6. The forces acting on an object are shown with vectors in the free body diagram below. Which vector accurately represents the net force on the object? 1. 2. 3. 4. A B C D
7. A 52-kg bike is moving along a smooth road at a constant velocity of 8.4 m/s. What is the net force acting on the bike?
1. 0 N
2. 190 N
3. 320 N
4. 510 N
 A B C D
8. A 3.3-kg block rests on a table. A 2.1-kg box rests on top of the block. What is the magnitude of the normal force exerted by the table on the block?
1. 12 N
2. 26 N
3. 32 N
4. 53 N
 A B C D
9. Two automobiles travel on a circular track at the same speed at different times. The first car is twice as massive as the second. Which describes the centripetal forces acting upon the two cars?
1. The centripetal force on the first car is half the centripetal force on the second car.
2. The centripetal forces on both cars are the same.
3. The centripetal force on the first car is double the centripetal force on the second car.
4. The centripetal force on the first car is quadruple the centripetal force on the second car.
 A B C D
10. Two carts of the same mass travel at the same speed toward each other. After they collide, each cart rebounds and moves in the opposite direction at the same speed as before the collision. What can be assumed about the collision?
1. Momentum and energy are both conserved during the collision.
2. Momentum and energy both change during the collision.
3. Momentum is conserved, but energy changes during the collision.
4. Momentum changes, but energy is conserved during the collision.
 A B C D
11. A player throws a ball at an average velocity of â€“40.0 m/s. Another player hits the ball back toward the thrower at a velocity of 30.0 m/s. If the ball has a mass of 0.144 kg, what is the magnitude of the impulse delivered to the ball to make it move in the opposite direction?
1. 1.44 Nâ€¢s
2. 4.32 Nâ€¢s
3. 5.76 Nâ€¢s
4. 10.1 Nâ€¢s
 A B C D
12. A 0.110-kg ball (ball X) moving at 1.20 m/s to the right, collides head-on with an identical ball (ball Y) moving to the left at a velocity of 0.600 m/s. Ball Y rebounds and reverses direction at a velocity of 0.800 m/s. What is the velocity of ball X following the collision?
1. 0.200 m/s to the left
2. 0.0924 m/s to the right
3. 0.0880 m/s to the right
4. 0.00440 m/s to the left
 A B C D
13. Can a small, light ball have the same momentum as a large, heavy ball?
1. no, because there is a difference in the inertia of the two balls
2. no, because there is a difference in the masses of the two balls
3. yes, because the small ball may be able to gain as much inertia as the large ball
4. yes, because the velocity of the small ball may be much greater than that of the large ball
 A B C D
14. A force of 50 N is required to hold an ideal spring stationary after the spring has been stretched 0.1 m from its equilibrium position. How much potential energy is stored in the stretched spring?
1. 50 J
2. 25 J
3. 5.0 J
4. 2.5 J
 A B C D
15. A spring is on a frictionless horizontal surface. One end of the spring is attached to a rigid wall. A 0.65-kg ball initially moving at 4.3 m/s collides with the open end of the spring. How much potential energy is stored in the spring when the velocity of the ball is 0 m/s?
1. 3.6 J
2. 3.9 J
3. 6.0 J
4. 6.4 J
 A B C D
16. How much power does it take to lift a 12-N object 0.87 m in 1.3 s?
1. 0.80 W
2. 8.0 W
3. 10. W
4. 18 W
 A B C D
17. A constant 3.0-N horizontal force is applied to a 0.10-kg object as it moves a distance of 0.20 m along a horizontal, frictionless surface. How much work does the force perform on the object?
1. 6.0 x 10-2 J
2. 3.0 x 10-2 J
3. 6.0 x 10-1 J
4. 3.0 x 10-1 J
 A B C D
18. A 2.00-kg brick falls from the top of a building 6.00 m above the ground. What is the kinetic energy of the brick just before it reaches the ground?
1. 118 J
2. 58.8 J
3. 12.0 J
4. 3.00 J
 A B C D
19.This diagram represents a wave with a frequency of 1.1 Hz. What is the speed of the wave? 1. 0.41 m/s
2. 1.7 m/s
3. 2.4 m/s
4. 3.0 m/s
 A B C D
20. A student walked up a flight of stairs. Later, the same student ran up the same flight of stairs in less time. What can be concluded about the relative amounts of work performed and power produced by the student in these instances?
1. The work performed was the same in both instances. The power was greater when the student ran up the stairs.
2. The work performed was greater when the student ran up the stairs. The power was the same in both instances.
3. The work and power were the same in both instances because it was the same student on the same stairs.
4. The work performed and the power produced were both less when the student was running up the stairs than when walking up the stairs. Additional North Carolina Exam Questions