Cutnell/Johnson Physics 8 th edition

Cutnell/JohnsonPhysics 8th edition • Classroom Response System Questions Chapter 3 Kinematics in Two Dimensions Reading Quiz Questions

3.1.1. Which one of the following statements concerning the displacement of an object is false? a) Displacement is a vector quantity that points from the initial position of an object to its final position. b) The magnitude of an object’s displacement is always equal to the distance it traveled from its initial position to its final position. c) The magnitude of an object’s displacement is the shortest distance from its initial position to its final position. d) The direction of an object’s displacement is indicated by an arrow that begins on the initial position of the object and ends on its final position. e) The length of the arrow representing an object’s displacement is proportional to its magnitude.

3.1.2. At time t = 0 s, the position vector of a sailboat is . Later, at time t, the sailboat has a position vector . Which of the following expressions correctly indicates the displacement of the sailboat during the time interval, tt0?

3.1.3. A park ranger wanted to measure the height of a tall tree. The ranger stood 6.10 m from the base of the tree; and he observed that his line of sight made an angle of 73.5° above the horizontal as he looked at the top of the tree. What is the height of the tree? a) 5.84 m b) 8.77 m c) 11.7 m d) 17.3 m e) 20.6 m

3.1.4. Which one of the following quantities is an object’s displacement divided by the elapsed time of the displacement? a) average velocity b) instantaneous velocity c) average displacement d) average acceleration e) instantaneous acceleration

3.1.5. Which one of the following quantities is the change in object’s velocity divided by the elapsed time as the elapsed time becomes very small? a) average velocity b) instantaneous velocity c) average displacement d) average acceleration e) instantaneous acceleration

3.1.6. How is the direction of the average acceleration determined? a) The direction of the average acceleration is the same as that of the displacement vector. b) The direction of the average acceleration is the same as that of the instantaneous velocity vector. c) The direction of the average acceleration is that of the vector subtraction of the initial velocity from the final velocity. d) The direction of the average acceleration is the same as that of the average velocity vector. e) The direction of the average acceleration is that of the vector addition of the initial velocity from the final velocity.

3.1.7. A delivery truck leaves a warehouse and travels 3.20 km east. The truck makes a right turn and travels 2.45 km south to arrive at its destination. What is the magnitude and direction of the truck’s displacement from the warehouse? a) 4.03 km, 37.4 south of east b) 2.30 km, 52.5 south of east c) 0.75 km, 37.8 south of east d) 2.40 km, 45.0 south of east e) 5.65 km, 52.5 south of east

3.1.8. While on a one-hour trip, a small boat travels 32 km north and then travels 45 km east. What is the boat's average speed for the one-hour trip? a) 39 km/h b) 55 km/h c) 77 km/h d) 89 km/h e) 96 km/h

3.1.9. While on a one-hour trip, a small boat travels 32 km north and then travels 45 km east. What is the direction of the boat's average velocity for the one-hour trip? a) 45 north of east b) 54 north of east c) 35 north of east d) 27 north of east e) due east

3.1.10. A truck drives due south for 1.8 km in 2.0 minutes. Then, the truck turns and drives due west for 1.8 km in 2.0 minutes. Which one of the following statements is correct? a) The average speed for the two segments is the same. The average velocity for the two segments is the same. b) The average speed for the two segments is not the same. The average velocity for the two segments is the same. c) The average speed for the two segments is the same. The average velocity for the two segments is not the same. d) The average speed for the two segments is not the same. The average velocity for the two segments is not the same.

3.2.1. In two-dimensional motion in the x-y plane, what is the relationship between the x part of the motion to the y part of the motion? a) The x part of the motion is independent of the y part of the motion. b) The y part of the motion goes as the square of the x part of the motion. c) The x part of the motion is linearly dependent on the y part of the motion. d) The x part of the motion goes as the square of the y part of the motion. e) If the y part of the motion is in the vertical direction, then x part of the motion is dependent on the y part.

3.2.2. Complete the following statement: In two-dimensional motion in the x-y plane, the x part of the motion and the y part of the motion are independent a) only if there is no acceleration in either direction. b) only if there is no acceleration in one of the directions. c) only if there is an acceleration in both directions. d) whether or not there is an acceleration in any direction. e) whenever the acceleration is in the y direction only.

3.3.1. A football is kicked at an angle 25 with respect to the horizontal. Which one of the following statements best describes the acceleration of the football during this event if air resistance is neglected? a) The acceleration is zero m/s2 at all times. b) The acceleration is zero m/s2 when the football has reached the highest point in its trajectory. c) The acceleration is positive as the football rises, and it is negative as the football falls. d) The acceleration starts at 9.8 m/s2 and drops to some constant lower value as the ball approaches the ground. e) The acceleration is 9.8 m/s2 at all times.

3.3.2. A baseball is hit upward and travels along a parabolic arc before it strikes the ground. Which one of the following statements is necessarily true? a) The velocity of the ball is a maximum when the ball is at the highest point in the arc. b) The x-component of the velocity of the ball is the same throughout the ball's flight. c) The acceleration of the ball decreases as the ball moves upward. d) The velocity of the ball is zero m/s when the ball is at the highest point in the arc. e) The acceleration of the ball is zero m/s2 when the ball is at the highest point in the arc.

3.3.3. Two cannons are mounted on a high cliff. Cannon A fires balls with twice the initial velocity of cannon B. Both cannons are aimed horizontally and fired. How does the horizontal range of cannon A compare to that of cannon B? • a) The range for both balls will be the same • The range of the cannon ball B is about 0.7 times that of cannon ball A. • c) The range of the cannon ball B is about 1.4 times that of cannon • ball A. • The range of the cannon ball B is about twice that of cannon ball A. • e) The range of the cannon ball B is about one-half that of cannon ball A.

3.3.4. Which one of the following statements concerning the range of a football is true if the football is kicked at an angle  with an initial speed v0? a) The range is independent of initial speed v0. b) The range is only dependent on the initial speed v0. c) The range is independent of the angle . d) The range is only dependent on the angle . e) The range is dependent on both the initial speed v0 and the angle .

3.3.5. A bullet is aimed at a target on the wall a distance L away from the firing position. Because of gravity, the bullet strikes the wall a distance Δybelow the mark as suggested in the figure. Note: The drawing is not to scale. If the distance L was half as large, and the bullet had the same initial velocity, how would Δybe affected? a) Δy will double. b) Δywill be half as large. c) Δywill be one fourth as large. d) Δywill be four times larger. e) It is not possible to determine unless numerical values are given for the distances.

3.3.6. A child throws a ball vertically upward at the school playground. Which one of the following quantities is (are) equal to zero at the highest point of the ball’s trajectory? Assume that at the time of release t = 0, the ball is at y = 0 m. a) instantaneous velocity b) displacement c) instantaneous acceleration d) average acceleration e) both instantaneous velocity and instantaneous acceleration

3.3.7. Which of the following is not a vector? a) position b) displacement c) average velocity d) centripetal acceleration e) range

3.3.8. Complete the following statement: In projectile motion, a) the horizontal motion depends on the vertical motion. b) the vertical motion depends on the horizontal motion. c) the horizontal acceleration depends on the vertical acceleration. d) the horizontal motion and the vertical motion are independent of each other. e) the vertical acceleration depends on the horizontal acceleration.

3.3.9. An airplane is flying horizontally at a constant velocity when a package is dropped from its cargo bay. Assuming no air resistance, which one of the following statements is correct? a) The package follows a curved path that lags behind the airplane. b) The package follows a straight line path that lags behind the airplane. c) The package follows a straight line path, but it is always vertically below the airplane. d) The package follows a curved path, but it is always vertically below the airplane. e) The package follows a curved path, but its horizontal position varies depending on the velocity of the airplane.

3.3.10. A ball is launched with an initial velocity as shown. Which one of the following arrows best represents the direction of the acceleration at point A? a) b) c) d) e) The acceleration at point A is zero m/s2.

3.3.11. A ball is launched with an initial velocity as shown. Which one of the following arrows best represents the direction of the velocity at point B? a) b) c) d) e) The velocity at point B is zero m/s.

3.4.1. At one point during the Tour de France bicycle race, three racers are riding along a straight, level section of road. The velocity of racer A relative to racer B is ; the velocity of A relative to C is ; and the velocity of C relative to B is . If = +6.0 m/s, and = +2.0 m/s, what is ? a) +2.0 m/s b) +4.0 m/s c) +8.0 m/s d) 4.0 m/s e) 2.0 m/s

3.4.2. Two private airplanes are taxiing at a small airport. Jim is in plane A rolling due south with respect to the ground. Samantha is in plane B rolling due west with respect to the ground. Samantha is in front of Jim and to his left. In what direction(s), relative to himself, does Jim see Samantha’s plane moving? a) due east b) due west c) due south d) to the south and to the east e) to the north and to the west

Cutnell/Johnson Physics 8 th edition