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

Where are we going? Are you coming back? What's that noise? Is that a gun? Do you smell something burning? Ooooohh... what's in heeeere?

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?

We are pleased that you made it through the final challenge where we pretended we were going to murder you. We are very very happy for your success. We are throwing a party in honor of your tremendous success. Place the device on the ground, then lie on your stomach with your arms at your sides. A party associate will arrive shortly to collect you for your party. Make no further attempt to leave the testing area. Assume the Party Escort Submission Position, or you will miss the party.

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