**Speed**

The rate at will a body travels is speed. The average speed is given by:

Average Speed = Distance/Time

**Units**

Ms | Meters per second |

Cms | Centimeters per second |

Kms | Kilometers per second |

Kmh | Kilometers per hour |

mph | Miles per hour |

**Distance and displacement**

Distance moved by an object in a particular direction is displacement. Distance is a scalar quantity and displacement is a vector.

**Speed and velocity**

Distance traveled per time taken is called velocity. Speed is a scalar quantity and Velocity is a vector.

velocity=change in displacement/time taken

**Displacement time graphs**

We can represent the changing position of moving object by drawing a displacement time graph.