Relative Motion, Distance, and Displacement
Relative Motion, Distance, and Displacement pt. 2
Speed and Velocity
Position vs. Time
Velocity vs. Time
100
Can one-dimensional motion be described with a zero distance traveled but nonzero displacement. Conversely, can it be described with zero displacement but a nonzero distance traveled?
One-dimensional motion can have zero distance traveled with a nonzero displacement. Displacement has both magnitude and direction; it can also have zero displacement with nonzero distance traveled because distance traveled has only magnitude.
One-dimensional motion can have zero distance traveled with a nonzero displacement. Displacement has both magnitude and direction, but it cannot have zero displacement with nonzero distance traveled because distance has only magnitude.
One-dimensional motion cannot have zero distance traveled with a nonzero displacement. Displacement has both magnitude and direction, but it can have zero displacement with nonzero distance traveled because distance has only magnitude and any motion will be the distance it moves.
One-dimensional motion cannot have zero distance traveled with a nonzero displacement. Displacement has both magnitude and direction; it cannot have zero displacement with nonzero distance traveled because distance has only magnitude.
C. One-dimensional motion cannot have zero distance traveled with a nonzero displacement. Displacement has both magnitude and direction, but it can have zero displacement with nonzero distance traveled because distance has only magnitude and any motion will be the distance it moves.
100
What is the difference between distance and displacement?
a. Distance has both magnitude and direction, while displacement has magnitude but no direction.
b. Distance has magnitude but no direction, while displacement has both magnitude and direction.
c. Distance has magnitude but no direction, while displacement has only direction.
d. There is no difference. Both distance and displacement have magnitude and direction.
b. Distance has magnitude but no direction, while displacement has both magnitude and direction.
100
A car travels 150 km north in 3 hours, then 50 km south in 1 hour. What is the car’s average velocity over the entire trip?
A) 50 km/h north
B) 25 km/h north
C) 25 km/h south
D) 100 km/h north
B) 25 km/h north
100
A position vs. time graph shows a straight line with a positive slope. What does this indicate about the object’s motion?
A. The object is at rest.
B. The object is moving at a constant velocity in the positive direction.
C. The object is accelerating.
D. The object is moving at a constant velocity in the negative direction.
B. The object is moving at a constant velocity in the positive direction.
100
What information could you obtain by looking at a velocity vs. time graph?
a. acceleration
b. direction of motion
c. reference frame of the motion
d. shortest path
a. acceleration
200
In which example would you be correct in describing an object in motion while your friend would also be correct in describing that same object as being at rest?
- You are driving a car toward the east and your friend drives past you in the opposite direction with the same speed. In your frame of reference, you will be in motion. In your friend’s frame of reference, you will be at rest.
- You are driving a car toward the east and your friend is standing at the bus stop. In your frame of reference, you will be in motion. In your friend’s frame of reference, you will be at rest.
- You are driving a car toward the east and your friend is standing at the bus stop. In your frame of reference, your friend will be moving toward the west. In your friend’s frame of reference, he will be at rest.
- You are driving a car toward the east and your friend is standing at the bus stop. In your frame of reference, your friend will be moving toward the east. In your friend’s frame of reference, he will be at rest.
C. You are driving a car toward the east and your friend is standing at the bus stop. In your frame of reference, your friend will be moving toward the west. In your friend’s frame of reference, he will be at rest.
200
Can one-dimensional motion have zero distance but a nonzero displacement? What about zero displacement but a nonzero distance?
a. One-dimensional motion can have zero distance with a nonzero displacement. Displacement has both magnitude and direction, and it can also have zero displacement with nonzero distance because distance has only magnitude.
b. One-dimensional motion can have zero distance with a nonzero displacement. Displacement has both magnitude and direction, but it cannot have zero displacement with nonzero distance because distance has only magnitude.
c. One-dimensional motion cannot have zero distance with a nonzero displacement. Displacement has both magnitude and direction, but it can have zero displacement with nonzero distance because distance has only magnitude and any motion will be the distance it moves.
d. One-dimensional motion cannot have zero distance with a nonzero displacement. Displacement has both magnitude and direction, and it cannot have zero displacement with nonzero distance because distance has only magnitude.
b. One-dimensional motion can have zero distance with a nonzero displacement. Displacement has both magnitude and direction, but it cannot have zero displacement with nonzero distance because distance has only magnitude.
200
A runner completes a 400 m lap around a circular track in 80 s. What is the runner’s average speed and average velocity?
A) 5 m/s; 0 m/s
B) 5 m/s; 5 m/s
C) 20 m/s; 0 m/s
D) 20 m/s; 20 m/s
A) 5 m/s; 0 m/s
200
A position vs. time graph has a line with zero slope. What does this tell you about the object?
A. The object is accelerating.
B. The object is moving at a constant positive velocity.
C. The object is at rest.
D. The object is moving at a constant negative velocity.
C. The object is at rest.
200
A velocity vs. time graph shows a horizontal line above the time axis. What does this indicate about the object’s motion?
a) The object is at rest.
b) The object is moving at a constant positive velocity.
c) The object is accelerating in the positive direction.
d) The object is accelerating in the negative direction.
b) The object is moving at a constant positive velocity.
300
What does your car’s odometer record?
displacement
distance
both distance and displacement
the sum of distance and displacement
b. distance
300
Why should you specify a reference frame when describing motion?
a. a description of motion depends on the reference frame
b. motion appears the same in all reference frames
c. reference frames affect the motion of an object
d. you can see motion better from certain reference frames
a. a description of motion depends on the reference frame
300
Cassie walked to her friend’s house with an average speed of 1.40 m/s. The distance between the houses is 205 m. How long did the trip take her?
146 s
0.01 s
2.50 min
287 s
a. 146 s
300
On a position vs. time graph, the slope of the line at any point represents:
A. Acceleration
B. Displacement
C. Instantaneous velocity
D. Average velocity
C. Instantaneous velocity
300
An object is moving along a straight path with constant acceleration. A velocity vs. time graph starts at 0 and ends at 10m/s, stretching over a time-span of 15s. What is the object’s net displacement?
a. 75m
b. 130m
c. 150m
d. cannot be determined from the information given
a. 75m
400
Two boats are traveling at equal and opposite velocities when they pass each other. How would the captain of each boat describe the motion of the other boat?
Each captain would describe other boat’s motion the same because motion is independent of reference frame.
Each captain will describe other boat’s motion as moving in the backward direction because they are in their own reference frames.
Each captain would describe the boats as moving differently because motion is a relative term.
Each captain would describe the other boat’s motion perpendicularly because they will perceive them as moving opposite to each other.
a. Each captain would describe other boat’s motion the same because motion is independent of reference frame.
400
If a biker rides west for 50 miles from his starting position, then turns and bikes back east 80 miles. What is his net displacement?
a. 130 miles
b. 30 miles east
c. 30 miles west
d. Cannot be determined from the information given
b. 30 miles east
400
Is it possible to determine a car’s instantaneous velocity from just the speedometer reading?
a. No, it reflects speed but not the direction.
b. No, it reflects the average speed of the car.
c. Yes, it sometimes reflects instantaneous velocity of the car.
d. Yes, it always reflects the instantaneous velocity of the car.
a. No, it reflects speed but not the direction.
400
A position vs. time graph is curved upward (concave up). What can be said about the object’s motion?
A. The object is at rest.
B. The object is slowing down.
C. The object is accelerating in the positive direction.
D. The object is moving at a constant velocity.
C. The object is accelerating in the positive direction.
400
On a velocity vs. time graph, the slope of the line represents:
a) Displacement
b) Speed
c) Acceleration
d) Position
c) Acceleration
500
Passenger A sits inside a moving train and throws a ball vertically upward. How would the motion of the ball be described by a fellow train passenger B and an observer C who is standing on the platform outside the train?
Passenger B sees that the ball has vertical, but no horizontal, motion. Observer C sees the ball has vertical as well as horizontal motion.
Passenger B sees the ball has vertical as well as horizontal motion. Observer C sees the ball has the vertical, but no horizontal, motion.
Passenger B sees the ball has horizontal but no vertical motion. Observer C sees the ball has vertical as well as horizontal motion.
Passenger B sees the ball has vertical as well as horizontal motion. Observer C sees the ball has horizontal but no vertical motion.
a. Passenger B sees that the ball has vertical, but no horizontal, motion. Observer C sees the ball has vertical as well as horizontal motion.
500
Maud sends her bowling ball straight down the center of the lane, getting a strike. The ball is brought back to the holder mechanically. What are the ball’s net displacement and distance traveled?
a. Displacement of the ball is twice the length of the lane, while the distance is zero.
b. Displacement of the ball is zero, while the distance is twice the length of the lane.
c. Both the displacement and distance for the ball are equal to zero.
d. Both the displacement and distance for the ball are twice the length of the lane.
b. Displacement of the ball is zero, while the distance is twice the length of the lane.
500
Rob drove to the nearest hospital with an average speed of v m/s in t seconds. In terms of t, if he drives home on the same path, but with an average speed of 3v m/s, how long is the return trip home?
a. t/6
b. t/3
c. 3t
d. 6t
b. t/3
500
A position vs. time graph shows a line with a negative slope. What does this indicate about the object?
A. The object is moving in the negative direction at a constant velocity.
B. The object is at rest.
C. The object is accelerating in the positive direction.
D. The object is moving in the positive direction at a constant velocity.
A. The object is moving in the negative direction at a constant velocity.
500
A graph of velocity vs. time of a ship coming into a harbor is shown.
Describe the acceleration of the ship based on the graph.
- The ship is moving in the forward direction at a steady rate. Then it accelerates in the forward direction and then decelerates.
- The ship is moving in the forward direction at a steady rate. Then it turns around and starts decelerating, while traveling in the reverse direction. It then accelerates, but slowly.
- The ship is moving in the forward direction at a steady rate. Then it decelerates in the forward direction, and then continues to slow down in the forward direction, but with more deceleration.
- The ship is moving in the forward direction at a steady rate. Then it decelerates in the forward direction, and then continues to slow down in the forward direction, but with less deceleration.
d. The ship is moving in the forward direction at a steady rate. Then it decelerates in the forward direction, and then continues to slow down in the forward direction, but with less deceleration.