Question

5. A satellite in a circular orbit just above the surface of the Earth (r = 1 Re) would need 8 km/sec to stay in orbit. If a missile is sent at that same speed straight up, how high will it get?

Answer 1

Hints: (1) The semimajor axis of an orbit depends only on the launch energy.(2) The trajectory of an object tossed straight up may be viewed as an ellipse of zero width.

Answer 2

gravitational force provides centripetal acceleration for satellite to move in its orbit
if a missile is sent at same speed?

using energy at surface of earth = energy at a height h (maximum) where kinetic energy is 0