A 0.500 kg projectile is launched straight up from the surface of the Earth, and attains a maximum height of 782.0 km above the surface of the Earth, before falling back down towards Earth. You can ignore air resistance in this problem. V Part A What is the change in gravitational potential energy (AU) of the Earth-projectile system, as the projectile travels upwards from the surface of the Earth to its highest point (in Joules)? ? 3831.8 Joules Submit Previous Answers Request Answer X Incorrect; Try Again; 5 attempts remaining Part B What was the initial velocity of the launched projectile (in m/s)? IVO AEd ? m/s Submit Request