Definition and examples of...

1. Distance and Displacement

1. Distance is a scalar quantity, which measures the full length of the object has gone through/between two things.
1. Example  
   In a 257 m running track, the distance between start point and end point is 257 m.

2. Displacement is a vector quantity, which is final subtracted by initial, become displacement.
1. Example
   In a 257 m running track, the displacement between start point and end point is 0 m.

2. Speed and Velocity

1. Speed is distance divided by time. As distance itself is a scalar quantity, speed is also a scalar quantity. It measures how fast someone or something is moving or operating.
1. Example

        Her maximum speed of running is 15 km per hour.  

2. Velocity is displacement divided by time. As displacement itself is a vector quantity, velocity is also a vector quantity. It measures the rate at which the the object change its position.
1. Example
   Her velocity from the start point to the end point of the running track is zero.

   

3. Acceleration and Deceleration

1. Acceleration is the rate of change in increasing velocity per unit over time.
1. Example
   Sports car has better acceleration than any other normal car.

   

2. Deceleration is the opposite of acceleration, which is the decreasing rate of velocity per unit over time.
1. Example
   She has been running for 1 hours non-stop, that she is too tired and her speed has been decelerating since 5 minutes ago.