Final answer:
Differentiating between speed and velocity, the phrases describe either speed, which is a scalar quantity, or velocity, which is a vector quantity including both magnitude and direction. Examples such as 'a train traveling 45 m/s north' describe velocity, while 'a cheetah running 97 km/h' refers to speed.
Step-by-step explanation:
The phrases given in the question can be categorized to describe either speed or velocity. The main difference between these two is that velocity includes a direction, making it a vector, while speed does not.
- The displacement of an object during a specific unit of time describes velocity because it includes both magnitude and direction.
- 'How fast or slow an object is moving and in what direction' also refers to velocity.
- 'How fast or slow an object is moving' describes speed, as no direction is mentioned.
- 'A cheetah running 97 km/h' represents speed, as no directional component is mentioned.
- 'A train traveling 45 m/s north' describes velocity, since it specifies a direction along with how fast the train is moving.
Lastly, in the case of the airplane passenger moving -4 m in 5 seconds, the average velocity would be calculated by dividing the displacement by the time, which results in -0.8 meters per second (m/s), with the negative sign indicating the direction of movement.