Escape Velocity 1.0.10 Cheats Why Does A Rocket Require An Escape Velocity To Leave The Atmosphere? Why Not Any Constant Speed?

Why does a rocket require an escape velocity to leave the atmosphere? Why not any constant speed? - escape velocity 1.0.10 cheats

I think that a missile to be able to go to 10 mph (in theory) must be abandoned as long as the fuel and the atmosphere. What is the rate of release of all this?