I have been working on this question for a while now, and it's supposed to be truly easy, but I can't obtain the answer can you sort of guide me through this question, and show me the equations you used?
Question: At the Earth's surface, a projectile is launched straight up at a speed of 9.1 km/s. To what height will it rise?
I need help to solve the above question and ignore air resistance and the rotation of the Earth.