Force and Motion 4 of 40 II Pause
Susan and Michael travel on separate trains. Susan's train moves westward at a constant speed of 5 meters per second. Michael's train
moves eastward at a constant speed of 7 meters per second. How fast is Susan's train moving relative to Michael's train?

Explanation:

Given:

Represent

- Susan's velocity with

- Michael's velocity with

eastwards

westwards

Required

Determine how fast is relative to

From the question, one train moves eastwards while the other moves westwards.

This means that travel in opposite travel and the relative speed (V) is calculated as:

Substitute values for and

Hence, the Susan's train is moving 2m/s in relative to Michael's train

the correct answer is:

a population changes in response to a change in the environment.