thrust

I said I would come back to this, and I am. I am a man of my word. Yesterday, I posted a link to a video of this really cool water rocket thingy. How does this work? What is the physics going on here? I think this can be best explained with the momentum principle. Let me start by pretending like I have some object that shoots out a piece of water (or really it could be anything). Also, let me pretend like this is in space ore something where there are no external forces. Above is a before and after picture. Initially, there is something (the box) with water inside. Through some process…

Let's say we're having a nice day here on Earth; the Sun is shining, the clouds are sparse, and everything is just looking like a peach: And then Lucas goes and tells me, Oh my God, Ethan! It's Armageddon! An asteroid is coming straight for us! You've got to stop it! Really? Me? Well, how would I do it? Let's say we've got some reasonably good asteroid tracking going on, and we've got about 2 months before the asteroid is actually going to hit us. We'd like to do something with the situation on the left, to avoid the situation on the right: Well, what we really have to do is change the…