Train A leaves City A at 10 am, avg speeds 200 mph. Train B leaves City B 10:20 their time, 220 mph. Tweather is clear. When will the 2 trains collide

Even if they were on the same track, we couldn't answer without knowing the timezone of City B and City A, the distance between the cities, and at what point they cross into any timezones between the two cities.

when they reach the crash site.

2029 due to the curvature of the moon

(a) never, they're on different tracks
(b) Certainly not

Just after the stop where I board one of the trains.

Assuming they are both on the same track, in the same time zone and headed towards each other and that City A and City B are X miles apart and that X is at least 66.7 miles apart: They will collide at time T were X = the distance between the cities and T = (X- 66.7M)/440 MH)

Tesla would have an opinion only if they were electromagnetic trains.

At 200 or 220 mph, I think they are mag-levs, so YES, he cares.

Using lines of longitude its easy to work out the distance of 20 minutes. Clue....1 degree=15 mins.

When the two trains physically impact one another.