Hi there, I have a question here: "An asteroid is measured to have a speed relative to the Earth of 15 km/s while it is still far away. What is the speed of impact of the asteroid with the Earth?" I'm stumped. I don't even know where to start with this one -- it doesn't talk about how far "far" means, and you have nothing on the mass so I can't even calculate the new velocity. Does anyone have at least a hint of where to start with this one?