If we assume portals obey https://en.wikipedia.org/wiki/Galilean_invariance, then there’s no difference between “the tram|portal is moving and the people are stationary” and “the tram|portal is stationary and the people are moving.” The outcome should be the same.
B.
Speedy thing goes in. Speedy thing comes out.
Although it kind of depends how fast the tram is going.
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If we assume portals obey https://en.wikipedia.org/wiki/Galilean_invariance, then there’s no difference between “the tram|portal is moving and the people are stationary” and “the tram|portal is stationary and the people are moving.” The outcome should be the same.