I have a 3 part question, and I have managed to get 2 of the three parts, but I can not figure out the 3rd for the life of me. A projectile is shot directly away from Earth's surface. Neglect the rotation of Earth. (C) What is the least initial mechanical energy required at launch if the projectile is to escape earth? I kind of thought i should be using the escape speed of earth (11.2 km/s or 11200 m/s) and calculate Ek. However, I have no mass, so I'm not quite sure if thats the right way to approach the problem. Any thoughts? Many thanks!