I ask you again. Do you really happen to live in London. If not you are just assuming things. And if you really live in London, you are just falsifying the speed of commuter trains. Please, be very honest about what you say and do not insist on something impractical that shows your mean ego.
Now, enjoy reading the citation from the Internet. It says of an average speed of 33 kph speed for a London commuter train. I am not talking here about the medium distance trains.
"The average speed on the Underground is 20.5 mph (33.0 km/h). Outside the tunnels of central London, many lines' trains tend to travel at over 40 mph (64 km/h) in the suburban and countryside areas".
So, no doubt, you live in London. Better you change your flag to BD and Barisal.
No I live 50 kms away from London but travel regularly into London.
Why are you repeatedly questioning the speeds on the London underground? It seems a strange thing to do even if you are certain you are correct.
Like I say the electric underground trains are already doing 40km/h before they have even completely left the station and so why would they not be capable of going at 100km/h when the distance between stations is 2-3km?
The maximum acceration of a London underground train is 1.3m/s^2 and so using the below physics equation of motion:
v^2 = u^2 + 2as, with v being final velocity, u initial velocity, a the acceleration and s the distance.
Let us say the train accelerates at 1 m/s^2 on average for the first 1000m between stations.
v^2 = 0^2 + 2 X 1 X 1000
V^2 = 2000
v = Square Root(2000) = 45m/s which is way more than 100km/h.
If you do not believe these speeds then just move on as it is not worth debating further.