Question

Zero, a hypothetical planet, has a mass of 5.8 x 1023 kg, a radius of 2.7 x 106 m, and no atmosphere. a 10 kg space probe is to be launched vertically from its surface. (a) if the probe is launched with an initial kinetic energy of 5.0 x 107 j, what will be its kinetic energy when it is 4.0 x 106 m from the center of zero? (b) if the probe is to achieve a maximum distance of 8.0 x 106 m from the center of zero, with what initial kinetic energy must it be launched from the surface of zero?

Answer 1

To answer these questions just use the equations for potential energy using the mass and heights described. the potential energy at the prescribed heights = the initial kinetic energy required to reach that height.

Make sure you calculate the force of gravity on the surface using the radius of the planet.