It may seem like the block should accelerate, since it is moving relative to the "piston", but it is not moving relative to the portal, as portals are massless/volumeless and do not actually occupy any space.
since portal a is moving down at say 100mph, and portal b is not moving at all, whatever enters portal a, at 100mph, will have to exit portal b at the same speed
negative.
Imagine the piston is pumping up and down. The companion cube never moves. hell I imagine that, being centered on the blue portal, and getting pushed through esentially, that it would fall back into the orange portal and land back on the platform or bounce off depending on the postion of the blue portal above the pedestal.
also fuck that picture in it's stupid portal ass....
Get:
a) Empty toilet paper roll.
b) small object. Maybe a dice or a marble.
Place small object on table. Take roll of toilet paper in your hands and slam it down as hard as you can over the marble.
Will marble go flying out of the roll of toilet paper as you slam it over marble? No.
It's A, as we all know inside, trolling or not. However, if you are strictly speaking about it in the game: it will either not go through the portal all or fly out kind of like B depending on how you approach it.
Just the first decentish example I found:
I know there are some better videos just don't feel like searching all day for them.
edit: fixed wording
lol Math is hard.
but portals don't stay on moving objects.. ):
On the portal thing you're all wrong so far. You would simply see the corner of the block that is poking out of the portal moving downward toward the platform. There is no acceleration of the block or momentum transfer. The top portal would cover the block, revealing maybe one of it's corners as it connected with the bottom portion, assuming it stopped on contact with the horizontal platform. There would be no plop or projection.
I think it goes into the new portal, but since there's no motion, it just falls back onto the platform it was originally on.