Question

kiley went 5.7 km/h north and then went 5.8 km/h west. from start to finish, she went 8.1 km/h northwest. which best describes the numbers?
5.7 km/h north and 5.8 km/h west are instantaneous speeds, while 8.1 km/h northwest is the average speed
5.7 km/h north and 5.8 km/h west are average speeds, while 8.1 km/h northwest is the instantaneous speed
5.7 km/h north and 5.8 km/h west are average velocities, while 8.1 km/h northwest is the instantaneous velocity
5.7 km/h north and 5.8 km/h west are instantaneous velocities, while 8.1 km/h northwest is the average velocity

Explanation:

Velocity has both magnitude and direction. The 57 km/h north and 58 km/h west are velocities in different directions over some time - interval (average velocities). The 81 km/h northwest is the resultant of these two velocities over the same time - interval, which is also an average velocity considering the overall motion from start to finish.

Answer:

C. 57 km/h north and 58 km/h west are average velocities, while 81 km/h northwest is the resultant average velocity.