a) It is absolute, so it does not change.
b) Inertial ones.
c) Inside the train the time will slow down relatively to the outside clock. So if one travel at nearly the speed if light for 2 hours on his clock, for outdoor observers it will look like 3 hours.
Answer:
Tangential speed or Rotational speed
Average velocity over a given time interval is the distance traveled divided by the time:
Double displacement...I think
Average velocity is calculated as the division of displacement and change in time so the answer would be 804 km/36000 s=0.02 m/s
