Question

chapter review
concept items
2.1 relative motion, distance, and displacement

1. 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.

1. 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?

a. 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 friends frame of reference, you will be at rest.
b. 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 friends frame of reference, you 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 friends frame of reference, he will be at rest.
d. 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 friends frame of reference, he will be at rest.

1. what does your cars odometer record?

a. displacement
b. distance
c. both distance and displacement
d. the sum of distance and displacement
2.2 speed and velocity

1. in the definition of velocity, what physical quantity is changing over time?

a. speed
b. distance
c. magnitude of displacement
d. position vector

1. which of the following best describes the relationship between instantaneous velocity and instantaneous speed?

a. both instantaneous speed and instantaneous velocity are the same, even when there is a change in direction.
b. instantaneous speed and instantaneous velocity cannot be the same even if there is no change in direction of motion.
c. magnitude of instantaneous velocity is equal to instantaneous speed.
d. magnitude of instantaneous velocity is always greater than instantaneous speed.
2.3 position vs. time graphs

1. use the graph to describe what the runners motion looks like.

how are average velocity for only the first four seconds and instantaneous velocity related? what is the runners net displacement over the time shown?
a. the net displacement is 12 m and the average velocity is equal to the instantaneous velocity.
b. the net displacement is 12 m and the average velocity

Explanation:

1.

Distance is a scalar quantity representing the total path length traveled, while displacement is a vector quantity representing the change in position from the starting - point to the ending - point. In one - dimensional motion, distance cannot be zero if there is motion because it measures the total path covered. Displacement can be zero if an object returns to its starting point after moving.

Motion is relative. When considering different frames of reference, an object can be in motion relative to one observer and at rest relative to another. In the case of a moving car and a stationary person at a bus stop, from the driver's frame of reference, the person at the bus stop is moving in the opposite direction, and from the person at the bus stop's frame of reference, they are at rest.

An odometer in a car measures the total length of the path traveled by the car, which is the distance. It does not account for the direction of motion, so it does not measure displacement.

Answer:

d. One - dimensional motion cannot have zero distance with a nonzero displacement. Displacement has both magnitude and direction, and it can have zero displacement with nonzero distance because distance has only magnitude.

2.