# What are some examples of relative speed?

May 15, 2018

A passenger in a vagoon walking against the train direction, etc.

#### Explanation:

There are some examples on this

1. If a passenger in a vagoon walking against the train direction, of course the train speed is greater and ${v}_{n} = {v}_{t} - {v}_{p}$ is the speed. In this formula ${v}_{n}$ is the net speed and ${v}_{t}$ and ${v}_{p}$ are train speed and passenger walking speed respectively.

2. If there is a river flowing at a constant speed, and a swimmer swimming within the river course (in the same direction), the net speed ${v}_{n} = {v}_{r} + {v}_{s}$
${v}_{n}$ is the net speed and ${v}_{r}$ and ${v}_{s}$ are river speed and swimmer's speed respectively.

3. If there are two athletes competing against each other on the same direction on the track, it is also a example.

4. Two airplanes flying on the opposite directions with different speeds.

etc.