Momentum, a function of mass and velocity, is conserved between portals. In layman's terms, speedy thing goes in, speedy thing comes out.

Congratulations, the test is now over.
All Aperture technologies remain safely operational up to 4000 degrees kelvin. Rest assured, that there is absolutely no chance of a dangerous equipment malfunction prior to your victory candescence. Thank you for participating in that Aperture Science Enrichment activity. Goodbye!

That thing you burned up isn't important to me; it's the fluid catalytic cracking unit. It makes shoes for orphans... nice job breaking it, hero.

You are kidding me. Did you just stuff that Aperture Science thing-we-don't-know-what-it-does into an Aperture Science Emergency Intelligence Incinerator?

You are not a good person. You know that, right? Good people don't get up here.