To teach relative velocity which is a concept hard to explain but much easier to illustrate. I use the following examples and have the students report back their answers:

1. Imagine two students are sitting in the passenger back seat of two vehicles traveling at the exact same speed of 50mph. If the students can only see each other through a narrow scope and can only view one another. How would they view each other’s motion?

2. Now image that car A accelerates to anew speed of 70mph? How would passenger B view the motion of passenger A? How would passenger A view the motion of passenger B?

3. What do you suppose is relative velocity?