When traveling in a train or any other vehicle, have you noticed how you continue to move forward when it stops.
You just experienced INERTIA!
Inertia is the tendency of a body to resist a change in motion or rest. When a vehicle stops, you tend to jerk forward before coming to a complete stop. In the same way, you will jerk backwards when the vehicle begins to move.
The phenomenon occurs because of Newton’s First Law of Motion: An object at rest (or motion ) will continue to be in the same state unless acted upon by an external force. Which means objects tend to “keep on doing what they’re doing,” unless disturbed.