A projectile is shot directly away from Earth's surface. Neglect the rotation of the Earth. What multiple of Earth's radius RE gives the radial distance $($from the Earth's center$)$ the projectile reaches if $($a$)$ its initial speed is $0\mathrm{.}606$ of the escape speed from Earth and $($b$)$ its initial kinetic energy is $0\mathrm{.}606$ of the kinetic energy required to escape Earth? $($Give your answers as unitless numbers.$)($c$)$ What is the least initial mechanical energy required at launch if the projectile is to escape Earth?