A 3Kg projectile is fired straight upward from earth's surface with a speed that is one-fourth the escape speed. Neglecting air resistance. a) What is the Kinetic energy of this projectile when it is launched?
A projectile with mass of 139 kg is launched straight up from the Earth's surface with an initial speed vi. What magnitude of vi enables the projectile to just reach a maximum height of 5.8RE, measured from the center of the Earth?