1. A scientific hypothesis may turn out to be right or it may turn out to be wrong. If it is a valid hypothesis, there must be a test for proving it <A) right. B) wrong.>
2. A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor <A) exactly below the midpoint of the ceiling. B) ahead of the midpoint of the ceiling. C) behind the midpoint of the ceiling. D) more information is needed to solve this problem. E) none of these. >
3. A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is <A) zero. B) less than 30 m/s but larger than zero.
C) about 30 m/s. D) more than 30 m/s. E) more information needed for an estimate. >
4. Which of the following is not a vector quantity? <A) velocity B) speed C) acceleration D) None are vector quantities. E) All are vector quantities.>
5. The two measurements necessary for calculating average speed are <A) acceleration and time. B) velocity and time. C) distance and time. D) distance and acceleration. E) velocity and distance. >
6. If an object falls with constant acceleration, the velocity of the object must <A) be constant also. B) continuously change by the same amount each second. C) continuously change by varying amounts depending on its speed. D) continuously decrease. E) none of these.>
7. When a rock thrown straight upwards gets to the exact top of its path, its <A) velocity is zero and its acceleration is zero. B) velocity is zero and its acceleration is about 10 meters per second per second. C) velocity is about 10 m/s and its acceleration is zero. D) velocity is about 10 m/s and its acceleration is about 10 meters per second per second. E) none of these.>
8. A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is <A) the same as the force on the 1-kg book. B) 10 times as much as the force on the 1-kg book. C) zero.>
9. The force required to maintain an object at a constant velocity in free space is equal to <A) zero. B) the mass of the object. C) the weight of the object. D) the force required to stop it. E) none of these. >
10. A ball player wishes to determine pitching speed by throwing a ball horizontally from an elevation of 5 m above the ground. The player sees the ball land 20 m down range. What is the player's pitching speed? <A) about 5 m/s B) about 10 m/s C) about 20 m/s D) about 25 m/s E) none of these >
11. A woman on the surface of the Earth has a mass of 50 kilograms and a weight of 490 newtons. If the woman were floating freely inside a space habitat far away from Earth, she would have <A) less weight and more mass. B) less weight and the same mass. C) less weight and less mass. D) more weight and less mass. E) none of these. >
12. A river 100 m wide flows due south at 1 m/s. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat reaches the east bank < A) due east of where it started. B) 141 m farther south than where it started. C) 100 m farther south than where it started. D) 100 m farther north than where it started. >
13. What prevents satellites such as the space shuttle from falling? <A) gravity B) the absence of air drag C) Nothing; they're falling continuously all around the Earth.>
14. According to Newton, doubling the distance between two interacting objects <A) divides by 2 the gravitational force between them. B) multiplies by 2 the gravitational force between them. C) divides by 4 the gravitational force between them. D) multiplies by 4 the gravitational force between them. >
15. Neglecting air resistance, which will roll from rest to the bottom of an incline first, an empty jar, or the same jar filled with peanut butter? <A) the filled jar B) the empty jar C) Both reach the bottom at the same time. >
16. When doing somersaults, you'll more easily rotate when your body is <A) straight. B) balled up. C) no difference.>
17. A torque acting on an object tends to produce <A) equilibrium. B) rotation. C) linear motion. D) velocity. E) a center of gravity. >
18. Whereas impulse involves the time that a force acts, work involves the < A) distance that a force acts. B) time and distance that a force acts. C) acceleration that a force produces. >
19. A flower pot of mass m falls from rest to the ground below, a distance h. Which statement is correct? <A) The speed of the pot when it hits the ground is proportional to h. B) The KE of the pot when it hits the ground is proportional to h. C) The KE of the pot when it hits the ground does not depend on m. D) The speed of the pot when it hits the ground depends on m. E) None of these is correct. >
20. Using 1000 J of work, a toy elevator is raised from the ground floor to the second floor in 20 seconds. How much power does the elevator use? <A) 20 W B) 50 W C) 100 W D) 1000 W E) 20,000 W >